Update to containerd 1.6.8

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <alexellis2@gmail.com>

.github/workflows/build.yaml

@@ -12,7 +12,7 @@ jobs:
       GO111MODULE: off
     strategy:
       matrix:
-        go-version: [1.17.x]
+        go-version: [1.18.x]
         os: [ubuntu-latest]
     runs-on: ${{ matrix.os }}
     steps:

.github/workflows/publish.yaml

@@ -9,7 +9,7 @@ jobs:
   publish:
     strategy:
       matrix:
-        go-version: [ 1.17.x ]
+        go-version: [ 1.18.x ]
         os: [ ubuntu-latest ]
     runs-on: ${{ matrix.os }}
     steps:

Makefile

@@ -1,7 +1,7 @@
 Version := $(shell git describe --tags --dirty)
 GitCommit := $(shell git rev-parse HEAD)
 LDFLAGS := "-s -w -X main.Version=$(Version) -X main.GitCommit=$(GitCommit)"
-CONTAINERD_VER := 1.6.2
+CONTAINERD_VER := 1.6.8
 CNI_VERSION := v0.9.1
 ARCH := amd64
 
@@ -33,7 +33,7 @@ hashgen:
 .PHONY: prepare-test
 prepare-test:
 	curl -sLSf https://github.com/containerd/containerd/releases/download/v$(CONTAINERD_VER)/containerd-$(CONTAINERD_VER)-linux-amd64.tar.gz > /tmp/containerd.tar.gz && sudo tar -xvf /tmp/containerd.tar.gz -C /usr/local/bin/ --strip-components=1
-	curl -SLfs https://raw.githubusercontent.com/containerd/containerd/v1.6.2/containerd.service | sudo tee /etc/systemd/system/containerd.service
+	curl -SLfs https://raw.githubusercontent.com/containerd/containerd/v1.6.8/containerd.service | sudo tee /etc/systemd/system/containerd.service
 	sudo systemctl daemon-reload && sudo systemctl start containerd
 	sudo /sbin/sysctl -w net.ipv4.conf.all.forwarding=1
 	sudo mkdir -p /opt/cni/bin

cloud-config.txt

@@ -10,7 +10,7 @@ packages:
  - git
 
 runcmd:
-- curl -sfL https://raw.githubusercontent.com/openfaas/faasd/master/hack/install.sh | sh -s -
+- curl -sfL https://raw.githubusercontent.com/openfaas/faasd/master/hack/install.sh | bash -s -
 - systemctl status -l containerd --no-pager
 - journalctl -u faasd-provider --no-pager
 - systemctl status -l faasd-provider --no-pager

docker-compose.yaml

@@ -1,7 +1,7 @@
 version: "3.7"
 services:
   basic-auth-plugin:
-    image: ghcr.io/openfaas/basic-auth:0.21.0
+    image: ghcr.io/openfaas/basic-auth:0.21.4
     environment:
       - port=8080
       - secret_mount_path=/run/secrets
@@ -56,7 +56,7 @@ services:
        - "127.0.0.1:9090:9090"
 
   gateway:
-    image: ghcr.io/openfaas/gateway:0.21.3
+    image: ghcr.io/openfaas/gateway:0.22.0
     environment:
       - basic_auth=true
       - functions_provider_url=http://faasd-provider:8081/

docs/DEV.md

@@ -20,7 +20,7 @@ See these instructions instead: [Testing patches](/docs/PATCHES.md)
 
     For Windows users, install [Git Bash](https://git-scm.com/downloads) along with multipass or vagrant. You can also use WSL1 or WSL2 which provides a Linux environment.
 
-    You will also need [containerd v1.6.2](https://github.com/containerd/containerd) and the [CNI plugins v0.9.1](https://github.com/containernetworking/plugins)
+    You will also need [containerd](https://github.com/containerd/containerd) and the [CNI plugins](https://github.com/containernetworking/plugins)
 
     [faas-cli](https://github.com/openfaas/faas-cli) is optional, but recommended.
 
@@ -88,7 +88,7 @@ You have three options - binaries for PC, binaries for armhf, or build from sour
 * Install containerd `x86_64` only
 
 ```bash
-export VER=1.6.2
+export VER=1.6.8
 curl -sSL https://github.com/containerd/containerd/releases/download/v$VER/containerd-$VER-linux-amd64.tar.gz > /tmp/containerd.tar.gz \
   && sudo tar -xvf /tmp/containerd.tar.gz -C /usr/local/bin/ --strip-components=1
 
@@ -100,7 +100,7 @@ containerd -version
     Building `containerd` on armhf is extremely slow, so I've provided binaries for you.
 
     ```bash
-    curl -sSL https://github.com/alexellis/containerd-armhf/releases/download/v1.6.2/containerd.tgz | sudo tar -xvz --strip-components=2 -C /usr/local/bin/
+    curl -sSL https://github.com/alexellis/containerd-armhf/releases/download/v1.6.8/containerd.tgz | sudo tar -xvz --strip-components=2 -C /usr/local/bin/
     ```
 
 * Or clone / build / install [containerd](https://github.com/containerd/containerd) from source:
@@ -112,7 +112,7 @@ containerd -version
     git clone https://github.com/containerd/containerd
     cd containerd
     git fetch origin --tags
-    git checkout v1.6.2
+    git checkout v1.6.8
 
     make
     sudo make install
@@ -123,7 +123,7 @@ containerd -version
 #### Ensure containerd is running
 
 ```bash
-curl -sLS https://raw.githubusercontent.com/containerd/containerd/v1.6.2/containerd.service > /tmp/containerd.service
+curl -sLS https://raw.githubusercontent.com/containerd/containerd/v1.6.8/containerd.service > /tmp/containerd.service
 
 # Extend the timeouts for low-performance VMs
 echo "[Manager]" | tee -a /tmp/containerd.service
@@ -237,7 +237,7 @@ export SUFFIX="-armhf"
 export SUFFIX="-arm64"
 
 # Then download
-curl -fSLs "https://github.com/openfaas/faasd/releases/download/0.13.0/faasd$SUFFIX" \
+curl -fSLs "https://github.com/openfaas/faasd/releases/download/0.16.2/faasd$SUFFIX" \
     -o "/tmp/faasd" \
     && chmod +x "/tmp/faasd" 
 sudo mv /tmp/faasd /usr/local/bin/

docs/README.md

@@ -0,0 +1,7 @@
+# Documentation
+
+- [Develop faasd](./DEV.md) - Instructions for building and testing faasd locally
+- [Testing faasd](./PATCHES.md) - Instructions for testing a patch for faasd
+- [Roadmap](./ROADMAP.md) - Overview of features, backlog and known issues
+- [Run faasd with multipass](./MULTIPASS.md) - Tutorial on how to run faasd on a local multipass VM
+- [Terraform modules](./TERRAFORM.md) - A collection of official and community provided terraform modules for faasd

docs/TERRAFORM.md

@@ -0,0 +1,14 @@
+# Terraform Modules for faasd
+
+| Terraform Module | Author | Origin | Status |
+|-----------|--------|--------|--------|
+| [faasd on DigitalOcean](https://github.com/openfaas/faasd/tree/master/docs/bootstrap/digitalocean-terraform) | OpenFaaS | Official | Active |
+| [faasd on DigitalOcean](https://github.com/jsiebens/terraform-digitalocean-faasd) | Johan Siebens | Community | Active |
+| [faasd on Google Cloud Platform](https://github.com/jsiebens/terraform-google-faasd) | Johan Siebens | Community | Active |
+| [faasd on Microsoft Azure ](https://github.com/jsiebens/terraform-azurerm-faasd) | Johan Siebens | Community | Active |
+| [faasd on Equinix Metal](https://github.com/jsiebens/terraform-equinix-faasd) | Johan Siebens | Community | Active |
+| [faasd on Scaleway](https://github.com/jsiebens/terraform-scaleway-faasd) | Johan Siebens | Community | Active |
+| [faasd on Amazon Web Services](https://github.com/jsiebens/terraform-aws-faasd) |Johan Siebens | Community | Active |
+| [faasd on Linode](https://github.com/itTrident/terraform-linode-faasd) | itTrident | Community | Active |
+| [faasd on Vultr](https://github.com/itTrident/terraform-vultr-faasd) | itTrident | Community | Active |
+| [faasd on Exoscale](https://github.com/itTrident/terraform-exoscale-faasd) | itTrident | Community | Active |

docs/bootstrap/cloud-config.tpl

@@ -6,8 +6,8 @@ packages:
  - git
 
 runcmd:
-- curl -sLSf https://github.com/containerd/containerd/releases/download/v1.6.2/containerd-1.6.2-linux-amd64.tar.gz > /tmp/containerd.tar.gz && tar -xvf /tmp/containerd.tar.gz -C /usr/local/bin/ --strip-components=1
-- curl -SLfs https://raw.githubusercontent.com/containerd/containerd/v1.6.2/containerd.service | tee /etc/systemd/system/containerd.service
+- curl -sLSf https://github.com/containerd/containerd/releases/download/v1.6.8/containerd-1.6.8-linux-amd64.tar.gz > /tmp/containerd.tar.gz && tar -xvf /tmp/containerd.tar.gz -C /usr/local/bin/ --strip-components=1
+- curl -SLfs https://raw.githubusercontent.com/containerd/containerd/v1.6.8/containerd.service | tee /etc/systemd/system/containerd.service
 - systemctl daemon-reload && systemctl start containerd
 - /sbin/sysctl -w net.ipv4.conf.all.forwarding=1
 - mkdir -p /opt/cni/bin
@@ -16,8 +16,8 @@ runcmd:
 - mkdir -p /var/lib/faasd/secrets/
 - echo ${gw_password} > /var/lib/faasd/secrets/basic-auth-password
 - echo admin > /var/lib/faasd/secrets/basic-auth-user
-- cd /go/src/github.com/openfaas/ && git clone --depth 1 --branch 0.13.0 https://github.com/openfaas/faasd
-- curl -fSLs "https://github.com/openfaas/faasd/releases/download/0.13.0/faasd" --output "/usr/local/bin/faasd" && chmod a+x "/usr/local/bin/faasd"
+- cd /go/src/github.com/openfaas/ && git clone --depth 1 --branch 0.16.2 https://github.com/openfaas/faasd
+- curl -fSLs "https://github.com/openfaas/faasd/releases/download/0.16.2/faasd" --output "/usr/local/bin/faasd" && chmod a+x "/usr/local/bin/faasd"
 - cd /go/src/github.com/openfaas/faasd/ && /usr/local/bin/faasd install
 - systemctl status -l containerd --no-pager
 - journalctl -u faasd-provider --no-pager

docs/bootstrap/digitalocean-terraform/cloud-config.tpl

@@ -6,4 +6,4 @@ echo ${gw_password} > /var/lib/faasd/secrets/basic-auth-password
 export FAASD_DOMAIN=${faasd_domain_name}
 export LETSENCRYPT_EMAIL=${letsencrypt_email}
 
-curl -sfL https://raw.githubusercontent.com/openfaas/faasd/master/hack/install.sh | sh -s -
+curl -sfL https://raw.githubusercontent.com/openfaas/faasd/master/hack/install.sh | bash -s -

go.mod

@@ -1,43 +1,45 @@
 module github.com/openfaas/faasd
 
-go 1.17
+go 1.18
 
 require (
+	github.com/alexellis/arkade v0.0.0-20220816075441-1a4d561feb3e
 	github.com/alexellis/go-execute v0.5.0
-	github.com/alexellis/k3sup v0.0.0-20220105194923-e2bb18116d36
 	github.com/compose-spec/compose-go v0.0.0-20200528042322-36d8ce368e05
-	github.com/containerd/containerd v1.6.2
-	github.com/containerd/go-cni v1.1.3
+	github.com/containerd/containerd v1.6.6
+	github.com/containerd/go-cni v1.1.6
 	github.com/coreos/go-systemd v0.0.0-20191104093116-d3cd4ed1dbcf
 	github.com/docker/cli v0.0.0-20191105005515-99c5edceb48d
-	github.com/docker/distribution v2.8.0+incompatible
+	github.com/docker/distribution v2.8.1+incompatible
 	github.com/docker/docker v17.12.0-ce-rc1.0.20191113042239-ea84732a7725+incompatible // indirect
-	github.com/docker/docker-credential-helpers v0.6.3 // indirect
 	github.com/docker/go-units v0.4.0
 	github.com/gorilla/mux v1.8.0
 	github.com/morikuni/aec v1.0.0
 	github.com/opencontainers/runtime-spec v1.0.3-0.20210326190908-1c3f411f0417
-	github.com/openfaas/faas-provider v0.18.9
-	github.com/openfaas/faas/gateway v0.0.0-20220124164130-cdb6badddaed
+	github.com/openfaas/faas-provider v0.19.1
+	github.com/openfaas/faas/gateway v0.0.0-20220811112234-2cdc7f308316
 	github.com/pkg/errors v0.9.1
 	github.com/sethvargo/go-password v0.2.0
-	github.com/spf13/cobra v1.2.1
+	github.com/spf13/cobra v1.5.0
 	github.com/spf13/pflag v1.0.5
-	github.com/vishvananda/netlink v1.1.1-0.20210330154013-f5de75959ad5
-	github.com/vishvananda/netns v0.0.0-20210104183010-2eb08e3e575f
-	golang.org/x/sys v0.0.0-20211216021012-1d35b9e2eb4e
-	k8s.io/apimachinery v0.22.5
+	github.com/vishvananda/netlink v1.2.1-beta.2
+	github.com/vishvananda/netns v0.0.0-20211101163701-50045581ed74
+	golang.org/x/sys v0.0.0-20220811171246-fbc7d0a398ab
+	k8s.io/apimachinery v0.24.3
 )
 
 require (
 	github.com/Microsoft/go-winio v0.5.1 // indirect
-	github.com/Microsoft/hcsshim v0.9.2 // indirect
+	github.com/Microsoft/hcsshim v0.9.4 // indirect
+	github.com/beorn7/perks v1.0.1 // indirect
+	github.com/cespare/xxhash/v2 v2.1.2 // indirect
 	github.com/containerd/cgroups v1.0.3 // indirect
 	github.com/containerd/continuity v0.2.2 // indirect
 	github.com/containerd/fifo v1.0.0 // indirect
 	github.com/containerd/ttrpc v1.1.0 // indirect
 	github.com/containerd/typeurl v1.0.2 // indirect
-	github.com/containernetworking/cni v1.0.1 // indirect
+	github.com/containernetworking/cni v1.1.1 // indirect
+	github.com/docker/docker-credential-helpers v0.6.3 // indirect
 	github.com/docker/go-connections v0.4.0 // indirect
 	github.com/docker/go-events v0.0.0-20190806004212-e31b211e4f1c // indirect
 	github.com/gogo/googleapis v1.4.0 // indirect
@@ -49,25 +51,30 @@ require (
 	github.com/inconshreveable/mousetrap v1.0.0 // indirect
 	github.com/klauspost/compress v1.11.13 // indirect
 	github.com/mattn/go-shellwords v1.0.10 // indirect
+	github.com/matttproud/golang_protobuf_extensions v1.0.2-0.20181231171920-c182affec369 // indirect
 	github.com/mitchellh/mapstructure v1.4.1 // indirect
 	github.com/moby/locker v1.0.1 // indirect
 	github.com/moby/sys/mountinfo v0.5.0 // indirect
 	github.com/moby/sys/signal v0.6.0 // indirect
 	github.com/opencontainers/go-digest v1.0.0 // indirect
-	github.com/opencontainers/image-spec v1.0.2-0.20211117181255-693428a734f5 // indirect
-	github.com/opencontainers/runc v1.1.0 // indirect
-	github.com/opencontainers/selinux v1.10.0 // indirect
+	github.com/opencontainers/image-spec v1.0.3-0.20211202183452-c5a74bcca799 // indirect
+	github.com/opencontainers/runc v1.1.2 // indirect
+	github.com/opencontainers/selinux v1.10.1 // indirect
+	github.com/prometheus/client_golang v1.12.2 // indirect
+	github.com/prometheus/client_model v0.2.0 // indirect
+	github.com/prometheus/common v0.35.0 // indirect
+	github.com/prometheus/procfs v0.7.3 // indirect
 	github.com/sirupsen/logrus v1.8.1 // indirect
 	github.com/xeipuuv/gojsonpointer v0.0.0-20190905194746-02993c407bfb // indirect
 	github.com/xeipuuv/gojsonreference v0.0.0-20180127040603-bd5ef7bd5415 // indirect
 	github.com/xeipuuv/gojsonschema v1.2.0 // indirect
 	go.opencensus.io v0.23.0 // indirect
-	golang.org/x/net v0.0.0-20211216030914-fe4d6282115f // indirect
-	golang.org/x/sync v0.0.0-20210220032951-036812b2e83c // indirect
+	golang.org/x/net v0.0.0-20220225172249-27dd8689420f // indirect
+	golang.org/x/sync v0.0.0-20220601150217-0de741cfad7f // indirect
 	golang.org/x/text v0.3.7 // indirect
 	google.golang.org/genproto v0.0.0-20211208223120-3a66f561d7aa // indirect
 	google.golang.org/grpc v1.43.0 // indirect
-	google.golang.org/protobuf v1.27.1 // indirect
+	google.golang.org/protobuf v1.28.0 // indirect
 	gopkg.in/inf.v0 v0.9.1 // indirect
 	gopkg.in/yaml.v2 v2.4.0 // indirect
 )

hack/build-containerd-arm64.sh

@@ -29,7 +29,7 @@ git clone https://github.com/containerd/containerd
 
 cd containerd
 git fetch origin --tags
-git checkout v1.6.2
+git checkout v1.6.8
 
 make
 sudo make install

hack/build-containerd-armhf.sh

@@ -29,7 +29,7 @@ git clone https://github.com/containerd/containerd
 
 cd containerd
 git fetch origin --tags
-git checkout v1.6.2
+git checkout v1.6.8
 
 make
 sudo make install

hack/build-containerd.sh

@@ -30,7 +30,7 @@ git clone https://github.com/containerd/containerd
 
 cd containerd
 git fetch origin --tags
-git checkout v1.6.2
+git checkout v1.6.8
 
 make
 sudo make install

hack/install.sh

@@ -7,6 +7,18 @@ set -e -x -o pipefail
 export OWNER="openfaas"
 export REPO="faasd"
 
+# On CentOS /usr/local/bin is not included in the PATH when using sudo. 
+# Running arkade with sudo on CentOS requires the full path
+# to the arkade binary. 
+export ARKADE=/usr/local/bin/arkade
+
+# When running as a startup script (cloud-init), the HOME variable is not always set.
+# As it is required for arkade to properly download tools, 
+# set the variable to /usr/local so arkade will download binaries to /usr/local/.arkade
+if [ -z "${HOME}" ]; then
+  export HOME=/usr/local
+fi
+
 version=""
 
 echo "Finding latest version from GitHub"
@@ -51,7 +63,7 @@ install_required_packages() {
     $SUDO apt-get install -y curl runc bridge-utils iptables
   elif $(has_yum); then
     $SUDO yum check-update -y
-    $SUDO yum install -y curl runc
+    $SUDO yum install -y curl runc iptables-services
   elif $(has_pacman); then
     $SUDO pacman -Syy
     $SUDO pacman -Sy curl runc bridge-utils
@@ -61,53 +73,31 @@ install_required_packages() {
   fi
 }
 
+install_arkade(){
+  curl -sLS https://get.arkade.dev | $SUDO sh
+  arkade --help
+}
+
 install_cni_plugins() {
   cni_version=v0.9.1
-  suffix=""
-  arch=$(uname -m)
-  case $arch in
-  x86_64 | amd64)
-    suffix=amd64
-    ;;
-  aarch64)
-    suffix=arm64
-    ;;
-  arm*)
-    suffix=arm
-    ;;
-  *)
-    fatal "Unsupported architecture $arch"
-    ;;
-  esac
-
-  $SUDO mkdir -p /opt/cni/bin
-  curl -sSL https://github.com/containernetworking/plugins/releases/download/${cni_version}/cni-plugins-linux-${suffix}-${cni_version}.tgz | $SUDO tar -xvz -C /opt/cni/bin
+  $SUDO $ARKADE system install cni --version ${cni_version} --path /opt/cni/bin --progress=false
 }
 
 install_containerd() {
-  arch=$(uname -m)
-  CONTAINERD_VER=1.6.2
-  case $arch in
-  x86_64 | amd64)
-    curl -sLSf https://github.com/containerd/containerd/releases/download/v${CONTAINERD_VER}/containerd-${CONTAINERD_VER}-linux-amd64.tar.gz | $SUDO tar -xvz --strip-components=1 -C /usr/local/bin/
-    ;;
-  armv7l)
-    curl -sSL https://github.com/alexellis/containerd-arm/releases/download/v${CONTAINERD_VER}/containerd-${CONTAINERD_VER}-linux-armhf.tar.gz | $SUDO tar -xvz --strip-components=1 -C /usr/local/bin/
-    ;;
-  aarch64)
-      curl -sLSf https://github.com/containerd/containerd/releases/download/v${CONTAINERD_VER}/containerd-${CONTAINERD_VER}-linux-arm64.tar.gz | $SUDO tar -xvz --strip-components=1 -C /usr/local/bin/
-
-    ;;
-  *)
-    fatal "Unsupported architecture $arch"
-    ;;
-  esac
-
+  CONTAINERD_VER=v1.6.8
   $SUDO systemctl unmask containerd || :
-  $SUDO curl -SLfs https://raw.githubusercontent.com/containerd/containerd/v${CONTAINERD_VER}/containerd.service --output /etc/systemd/system/containerd.service
-  $SUDO systemctl enable containerd
-  $SUDO systemctl start containerd
 
+  arch=$(uname -m)
+  if [ $arch == "armv7l" ]; then
+    $SUDO curl -fSLs "https://github.com/alexellis/containerd-arm/releases/download/v${CONTAINERD_VER}/containerd-${CONTAINERD_VER}-linux-armhf.tar.gz" --output "/tmp/containerd.tar.gz"
+    $SUDO tar -xvf /tmp/containerd.tar.gz -C /usr/local/bin/
+    $SUDO curl -fSLs https://raw.githubusercontent.com/containerd/containerd/v${CONTAINERD_VER}/containerd.service --output "/etc/systemd/system/containerd.service"
+    $SUDO systemctl enable containerd
+    $SUDO systemctl start containerd
+  else
+    $SUDO $ARKADE system install containerd --systemd --version v${CONTAINERD_VER}  --progress=false
+  fi
+  
   sleep 5
 }
 
@@ -144,24 +134,10 @@ install_faasd() {
 
 install_caddy() {
   if [ ! -z "${FAASD_DOMAIN}" ]; then
-    arch=$(uname -m)
-    case $arch in
-    x86_64 | amd64)
-      suffix="amd64"
-      ;;
-    aarch64)
-      suffix=-arm64
-      ;;
-    armv7l)
-      suffix=-armv7
-      ;;
-    *)
-      echo "Unsupported architecture $arch"
-      exit 1
-      ;;
-    esac
+    CADDY_VER=v2.4.3
+    arkade get --progress=false caddy -v ${CADDY_VER}
+    $SUDO install -m 755 $HOME/.arkade/bin/caddy /usr/local/bin/
 
-    curl -sSL "https://github.com/caddyserver/caddy/releases/download/v2.4.3/caddy_2.4.3_linux_${suffix}.tar.gz" | $SUDO tar -xvz -C /usr/bin/ caddy
     $SUDO curl -fSLs https://raw.githubusercontent.com/caddyserver/dist/master/init/caddy.service --output /etc/systemd/system/caddy.service
 
     $SUDO mkdir -p /etc/caddy
@@ -194,7 +170,8 @@ EOF
 }
 
 install_faas_cli() {
-  curl -sLS https://cli.openfaas.com | $SUDO sh
+  arkade get --progress=false faas-cli
+  $SUDO install -m 755 $HOME/.arkade/bin/faas-cli /usr/local/bin/
 }
 
 verify_system
@@ -203,6 +180,7 @@ install_required_packages
 $SUDO /sbin/sysctl -w net.ipv4.conf.all.forwarding=1
 echo "net.ipv4.conf.all.forwarding=1" | $SUDO tee -a /etc/sysctl.conf
 
+install_arkade
 install_cni_plugins
 install_containerd
 install_faas_cli

pkg/supervisor.go

@@ -11,7 +11,7 @@ import (
 	"strconv"
 	"strings"
 
-	"github.com/alexellis/k3sup/pkg/env"
+	"github.com/alexellis/arkade/pkg/env"
 	"github.com/compose-spec/compose-go/loader"
 	compose "github.com/compose-spec/compose-go/types"
 	"github.com/containerd/containerd"

prometheus.yml

@@ -26,3 +26,7 @@ scrape_configs:
   - job_name: 'gateway'
     static_configs:
     - targets: ['gateway:8082']
+
+  - job_name: 'provider'
+    static_configs:
+    - targets: ['faasd-provider:8081']

vendor/github.com/Microsoft/hcsshim/internal/hcs/system.go

@@ -4,17 +4,22 @@ import (
 	"context"
 	"encoding/json"
 	"errors"
+	"fmt"
 	"strings"
 	"sync"
 	"syscall"
+	"time"
 
 	"github.com/Microsoft/hcsshim/internal/cow"
 	"github.com/Microsoft/hcsshim/internal/hcs/schema1"
 	hcsschema "github.com/Microsoft/hcsshim/internal/hcs/schema2"
+	"github.com/Microsoft/hcsshim/internal/jobobject"
 	"github.com/Microsoft/hcsshim/internal/log"
+	"github.com/Microsoft/hcsshim/internal/logfields"
 	"github.com/Microsoft/hcsshim/internal/oc"
 	"github.com/Microsoft/hcsshim/internal/timeout"
 	"github.com/Microsoft/hcsshim/internal/vmcompute"
+	"github.com/sirupsen/logrus"
 	"go.opencensus.io/trace"
 )
 
@@ -28,7 +33,8 @@ type System struct {
 	waitBlock      chan struct{}
 	waitError      error
 	exitError      error
-	os, typ        string
+	os, typ, owner string
+	startTime      time.Time
 }
 
 func newSystem(id string) *System {
@@ -38,6 +44,11 @@ func newSystem(id string) *System {
 	}
 }
 
+// Implementation detail for silo naming, this should NOT be relied upon very heavily.
+func siloNameFmt(containerID string) string {
+	return fmt.Sprintf(`\Container_%s`, containerID)
+}
+
 // CreateComputeSystem creates a new compute system with the given configuration but does not start it.
 func CreateComputeSystem(ctx context.Context, id string, hcsDocumentInterface interface{}) (_ *System, err error) {
 	operation := "hcs::CreateComputeSystem"
@@ -127,6 +138,7 @@ func (computeSystem *System) getCachedProperties(ctx context.Context) error {
 	}
 	computeSystem.typ = strings.ToLower(props.SystemType)
 	computeSystem.os = strings.ToLower(props.RuntimeOSType)
+	computeSystem.owner = strings.ToLower(props.Owner)
 	if computeSystem.os == "" && computeSystem.typ == "container" {
 		// Pre-RS5 HCS did not return the OS, but it only supported containers
 		// that ran Windows.
@@ -195,7 +207,7 @@ func (computeSystem *System) Start(ctx context.Context) (err error) {
 	if err != nil {
 		return makeSystemError(computeSystem, operation, err, events)
 	}
-
+	computeSystem.startTime = time.Now()
 	return nil
 }
 
@@ -324,11 +336,115 @@ func (computeSystem *System) Properties(ctx context.Context, types ...schema1.Pr
 	return properties, nil
 }
 
-// PropertiesV2 returns the requested container properties targeting a V2 schema container.
-func (computeSystem *System) PropertiesV2(ctx context.Context, types ...hcsschema.PropertyType) (*hcsschema.Properties, error) {
-	computeSystem.handleLock.RLock()
-	defer computeSystem.handleLock.RUnlock()
+// queryInProc handles querying for container properties without reaching out to HCS. `props`
+// will be updated to contain any data returned from the queries present in `types`. If any properties
+// failed to be queried they will be tallied up and returned in as the first return value. Failures on
+// query are NOT considered errors; the only failure case for this method is if the containers job object
+// cannot be opened.
+func (computeSystem *System) queryInProc(ctx context.Context, props *hcsschema.Properties, types []hcsschema.PropertyType) ([]hcsschema.PropertyType, error) {
+	// In the future we can make use of some new functionality in the HCS that allows you
+	// to pass a job object for HCS to use for the container. Currently, the only way we'll
+	// be able to open the job/silo is if we're running as SYSTEM.
+	jobOptions := &jobobject.Options{
+		UseNTVariant: true,
+		Name:         siloNameFmt(computeSystem.id),
+	}
+	job, err := jobobject.Open(ctx, jobOptions)
+	if err != nil {
+		return nil, err
+	}
+	defer job.Close()
 
+	var fallbackQueryTypes []hcsschema.PropertyType
+	for _, propType := range types {
+		switch propType {
+		case hcsschema.PTStatistics:
+			// Handle a bad caller asking for the same type twice. No use in re-querying if this is
+			// filled in already.
+			if props.Statistics == nil {
+				props.Statistics, err = computeSystem.statisticsInProc(job)
+				if err != nil {
+					log.G(ctx).WithError(err).Warn("failed to get statistics in-proc")
+
+					fallbackQueryTypes = append(fallbackQueryTypes, propType)
+				}
+			}
+		default:
+			fallbackQueryTypes = append(fallbackQueryTypes, propType)
+		}
+	}
+
+	return fallbackQueryTypes, nil
+}
+
+// statisticsInProc emulates what HCS does to grab statistics for a given container with a small
+// change to make grabbing the private working set total much more efficient.
+func (computeSystem *System) statisticsInProc(job *jobobject.JobObject) (*hcsschema.Statistics, error) {
+	// Start timestamp for these stats before we grab them to match HCS
+	timestamp := time.Now()
+
+	memInfo, err := job.QueryMemoryStats()
+	if err != nil {
+		return nil, err
+	}
+
+	processorInfo, err := job.QueryProcessorStats()
+	if err != nil {
+		return nil, err
+	}
+
+	storageInfo, err := job.QueryStorageStats()
+	if err != nil {
+		return nil, err
+	}
+
+	// This calculates the private working set more efficiently than HCS does. HCS calls NtQuerySystemInformation
+	// with the class SystemProcessInformation which returns an array containing system information for *every*
+	// process running on the machine. They then grab the pids that are running in the container and filter down
+	// the entries in the array to only what's running in that silo and start tallying up the total. This doesn't
+	// work well as performance should get worse if more processess are running on the machine in general and not
+	// just in the container. All of the additional information besides the WorkingSetPrivateSize field is ignored
+	// as well which isn't great and is wasted work to fetch.
+	//
+	// HCS only let's you grab statistics in an all or nothing fashion, so we can't just grab the private
+	// working set ourselves and ask for everything else seperately. The optimization we can make here is
+	// to open the silo ourselves and do the same queries for the rest of the info, as well as calculating
+	// the private working set in a more efficient manner by:
+	//
+	// 1. Find the pids running in the silo
+	// 2. Get a process handle for every process (only need PROCESS_QUERY_LIMITED_INFORMATION access)
+	// 3. Call NtQueryInformationProcess on each process with the class ProcessVmCounters
+	// 4. Tally up the total using the field PrivateWorkingSetSize in VM_COUNTERS_EX2.
+	privateWorkingSet, err := job.QueryPrivateWorkingSet()
+	if err != nil {
+		return nil, err
+	}
+
+	return &hcsschema.Statistics{
+		Timestamp:          timestamp,
+		ContainerStartTime: computeSystem.startTime,
+		Uptime100ns:        uint64(time.Since(computeSystem.startTime).Nanoseconds()) / 100,
+		Memory: &hcsschema.MemoryStats{
+			MemoryUsageCommitBytes:            memInfo.JobMemory,
+			MemoryUsageCommitPeakBytes:        memInfo.PeakJobMemoryUsed,
+			MemoryUsagePrivateWorkingSetBytes: privateWorkingSet,
+		},
+		Processor: &hcsschema.ProcessorStats{
+			RuntimeKernel100ns: uint64(processorInfo.TotalKernelTime),
+			RuntimeUser100ns:   uint64(processorInfo.TotalUserTime),
+			TotalRuntime100ns:  uint64(processorInfo.TotalKernelTime + processorInfo.TotalUserTime),
+		},
+		Storage: &hcsschema.StorageStats{
+			ReadCountNormalized:  uint64(storageInfo.ReadStats.IoCount),
+			ReadSizeBytes:        storageInfo.ReadStats.TotalSize,
+			WriteCountNormalized: uint64(storageInfo.WriteStats.IoCount),
+			WriteSizeBytes:       storageInfo.WriteStats.TotalSize,
+		},
+	}, nil
+}
+
+// hcsPropertiesV2Query is a helper to make a HcsGetComputeSystemProperties call using the V2 schema property types.
+func (computeSystem *System) hcsPropertiesV2Query(ctx context.Context, types []hcsschema.PropertyType) (*hcsschema.Properties, error) {
 	operation := "hcs::System::PropertiesV2"
 
 	queryBytes, err := json.Marshal(hcsschema.PropertyQuery{PropertyTypes: types})
@@ -345,12 +461,66 @@ func (computeSystem *System) PropertiesV2(ctx context.Context, types ...hcsschem
 	if propertiesJSON == "" {
 		return nil, ErrUnexpectedValue
 	}
-	properties := &hcsschema.Properties{}
-	if err := json.Unmarshal([]byte(propertiesJSON), properties); err != nil {
+	props := &hcsschema.Properties{}
+	if err := json.Unmarshal([]byte(propertiesJSON), props); err != nil {
 		return nil, makeSystemError(computeSystem, operation, err, nil)
 	}
 
-	return properties, nil
+	return props, nil
+}
+
+// PropertiesV2 returns the requested compute systems properties targeting a V2 schema compute system.
+func (computeSystem *System) PropertiesV2(ctx context.Context, types ...hcsschema.PropertyType) (_ *hcsschema.Properties, err error) {
+	computeSystem.handleLock.RLock()
+	defer computeSystem.handleLock.RUnlock()
+
+	// Let HCS tally up the total for VM based queries instead of querying ourselves.
+	if computeSystem.typ != "container" {
+		return computeSystem.hcsPropertiesV2Query(ctx, types)
+	}
+
+	// Define a starter Properties struct with the default fields returned from every
+	// query. Owner is only returned from Statistics but it's harmless to include.
+	properties := &hcsschema.Properties{
+		Id:            computeSystem.id,
+		SystemType:    computeSystem.typ,
+		RuntimeOsType: computeSystem.os,
+		Owner:         computeSystem.owner,
+	}
+
+	logEntry := log.G(ctx)
+	// First lets try and query ourselves without reaching to HCS. If any of the queries fail
+	// we'll take note and fallback to querying HCS for any of the failed types.
+	fallbackTypes, err := computeSystem.queryInProc(ctx, properties, types)
+	if err == nil && len(fallbackTypes) == 0 {
+		return properties, nil
+	} else if err != nil {
+		logEntry.WithError(fmt.Errorf("failed to query compute system properties in-proc: %w", err))
+		fallbackTypes = types
+	}
+
+	logEntry.WithFields(logrus.Fields{
+		logfields.ContainerID: computeSystem.id,
+		"propertyTypes":       fallbackTypes,
+	}).Info("falling back to HCS for property type queries")
+
+	hcsProperties, err := computeSystem.hcsPropertiesV2Query(ctx, fallbackTypes)
+	if err != nil {
+		return nil, err
+	}
+
+	// Now add in anything that we might have successfully queried in process.
+	if properties.Statistics != nil {
+		hcsProperties.Statistics = properties.Statistics
+		hcsProperties.Owner = properties.Owner
+	}
+
+	// For future support for querying processlist in-proc as well.
+	if properties.ProcessList != nil {
+		hcsProperties.ProcessList = properties.ProcessList
+	}
+
+	return hcsProperties, nil
 }
 
 // Pause pauses the execution of the computeSystem. This feature is not enabled in TP5.

vendor/github.com/Microsoft/hcsshim/internal/hns/hnspolicy.go

@@ -21,10 +21,11 @@ const (
 )
 
 type NatPolicy struct {
-	Type         PolicyType `json:"Type"`
-	Protocol     string     `json:",omitempty"`
-	InternalPort uint16     `json:",omitempty"`
-	ExternalPort uint16     `json:",omitempty"`
+	Type                 PolicyType `json:"Type"`
+	Protocol             string     `json:",omitempty"`
+	InternalPort         uint16     `json:",omitempty"`
+	ExternalPort         uint16     `json:",omitempty"`
+	ExternalPortReserved bool       `json:",omitempty"`
 }
 
 type QosPolicy struct {

vendor/github.com/Microsoft/hcsshim/internal/jobobject/iocp.go

@@ -0,0 +1,111 @@
+package jobobject
+
+import (
+	"context"
+	"fmt"
+	"sync"
+	"unsafe"
+
+	"github.com/Microsoft/hcsshim/internal/log"
+	"github.com/Microsoft/hcsshim/internal/queue"
+	"github.com/Microsoft/hcsshim/internal/winapi"
+	"github.com/sirupsen/logrus"
+	"golang.org/x/sys/windows"
+)
+
+var (
+	ioInitOnce sync.Once
+	initIOErr  error
+	// Global iocp handle that will be re-used for every job object
+	ioCompletionPort windows.Handle
+	// Mapping of job handle to queue to place notifications in.
+	jobMap sync.Map
+)
+
+// MsgAllProcessesExited is a type representing a message that every process in a job has exited.
+type MsgAllProcessesExited struct{}
+
+// MsgUnimplemented represents a message that we are aware of, but that isn't implemented currently.
+// This should not be treated as an error.
+type MsgUnimplemented struct{}
+
+// pollIOCP polls the io completion port forever.
+func pollIOCP(ctx context.Context, iocpHandle windows.Handle) {
+	var (
+		overlapped uintptr
+		code       uint32
+		key        uintptr
+	)
+
+	for {
+		err := windows.GetQueuedCompletionStatus(iocpHandle, &code, &key, (**windows.Overlapped)(unsafe.Pointer(&overlapped)), windows.INFINITE)
+		if err != nil {
+			log.G(ctx).WithError(err).Error("failed to poll for job object message")
+			continue
+		}
+		if val, ok := jobMap.Load(key); ok {
+			msq, ok := val.(*queue.MessageQueue)
+			if !ok {
+				log.G(ctx).WithField("value", msq).Warn("encountered non queue type in job map")
+				continue
+			}
+			notification, err := parseMessage(code, overlapped)
+			if err != nil {
+				log.G(ctx).WithFields(logrus.Fields{
+					"code":       code,
+					"overlapped": overlapped,
+				}).Warn("failed to parse job object message")
+				continue
+			}
+			if err := msq.Enqueue(notification); err == queue.ErrQueueClosed {
+				// Write will only return an error when the queue is closed.
+				// The only time a queue would ever be closed is when we call `Close` on
+				// the job it belongs to which also removes it from the jobMap, so something
+				// went wrong here. We can't return as this is reading messages for all jobs
+				// so just log it and move on.
+				log.G(ctx).WithFields(logrus.Fields{
+					"code":       code,
+					"overlapped": overlapped,
+				}).Warn("tried to write to a closed queue")
+				continue
+			}
+		} else {
+			log.G(ctx).Warn("received a message for a job not present in the mapping")
+		}
+	}
+}
+
+func parseMessage(code uint32, overlapped uintptr) (interface{}, error) {
+	// Check code and parse out relevant information related to that notification
+	// that we care about. For now all we handle is the message that all processes
+	// in the job have exited.
+	switch code {
+	case winapi.JOB_OBJECT_MSG_ACTIVE_PROCESS_ZERO:
+		return MsgAllProcessesExited{}, nil
+	// Other messages for completeness and a check to make sure that if we fall
+	// into the default case that this is a code we don't know how to handle.
+	case winapi.JOB_OBJECT_MSG_END_OF_JOB_TIME:
+	case winapi.JOB_OBJECT_MSG_END_OF_PROCESS_TIME:
+	case winapi.JOB_OBJECT_MSG_ACTIVE_PROCESS_LIMIT:
+	case winapi.JOB_OBJECT_MSG_NEW_PROCESS:
+	case winapi.JOB_OBJECT_MSG_EXIT_PROCESS:
+	case winapi.JOB_OBJECT_MSG_ABNORMAL_EXIT_PROCESS:
+	case winapi.JOB_OBJECT_MSG_PROCESS_MEMORY_LIMIT:
+	case winapi.JOB_OBJECT_MSG_JOB_MEMORY_LIMIT:
+	case winapi.JOB_OBJECT_MSG_NOTIFICATION_LIMIT:
+	default:
+		return nil, fmt.Errorf("unknown job notification type: %d", code)
+	}
+	return MsgUnimplemented{}, nil
+}
+
+// Assigns an IO completion port to get notified of events for the registered job
+// object.
+func attachIOCP(job windows.Handle, iocp windows.Handle) error {
+	info := winapi.JOBOBJECT_ASSOCIATE_COMPLETION_PORT{
+		CompletionKey:  job,
+		CompletionPort: iocp,
+	}
+	_, err := windows.SetInformationJobObject(job, windows.JobObjectAssociateCompletionPortInformation, uintptr(unsafe.Pointer(&info)), uint32(unsafe.Sizeof(info)))
+	return err
+}

vendor/github.com/Microsoft/hcsshim/internal/jobobject/jobobject.go

@@ -0,0 +1,538 @@
+package jobobject
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"sync"
+	"unsafe"
+
+	"github.com/Microsoft/hcsshim/internal/queue"
+	"github.com/Microsoft/hcsshim/internal/winapi"
+	"golang.org/x/sys/windows"
+)
+
+// This file provides higher level constructs for the win32 job object API.
+// Most of the core creation and management functions are already present in "golang.org/x/sys/windows"
+// (CreateJobObject, AssignProcessToJobObject, etc.) as well as most of the limit information
+// structs and associated limit flags. Whatever is not present from the job object API
+// in golang.org/x/sys/windows is located in /internal/winapi.
+//
+// https://docs.microsoft.com/en-us/windows/win32/procthread/job-objects
+
+// JobObject is a high level wrapper around a Windows job object. Holds a handle to
+// the job, a queue to receive iocp notifications about the lifecycle
+// of the job and a mutex for synchronized handle access.
+type JobObject struct {
+	handle     windows.Handle
+	mq         *queue.MessageQueue
+	handleLock sync.RWMutex
+}
+
+// JobLimits represents the resource constraints that can be applied to a job object.
+type JobLimits struct {
+	CPULimit           uint32
+	CPUWeight          uint32
+	MemoryLimitInBytes uint64
+	MaxIOPS            int64
+	MaxBandwidth       int64
+}
+
+type CPURateControlType uint32
+
+const (
+	WeightBased CPURateControlType = iota
+	RateBased
+)
+
+// Processor resource controls
+const (
+	cpuLimitMin  = 1
+	cpuLimitMax  = 10000
+	cpuWeightMin = 1
+	cpuWeightMax = 9
+)
+
+var (
+	ErrAlreadyClosed = errors.New("the handle has already been closed")
+	ErrNotRegistered = errors.New("job is not registered to receive notifications")
+)
+
+// Options represents the set of configurable options when making or opening a job object.
+type Options struct {
+	// `Name` specifies the name of the job object if a named job object is desired.
+	Name string
+	// `Notifications` specifies if the job will be registered to receive notifications.
+	// Defaults to false.
+	Notifications bool
+	// `UseNTVariant` specifies if we should use the `Nt` variant of Open/CreateJobObject.
+	// Defaults to false.
+	UseNTVariant bool
+	// `IOTracking` enables tracking I/O statistics on the job object. More specifically this
+	// calls SetInformationJobObject with the JobObjectIoAttribution class.
+	EnableIOTracking bool
+}
+
+// Create creates a job object.
+//
+// If options.Name is an empty string, the job will not be assigned a name.
+//
+// If options.Notifications are not enabled `PollNotifications` will return immediately with error `errNotRegistered`.
+//
+// If `options` is nil, use default option values.
+//
+// Returns a JobObject structure and an error if there is one.
+func Create(ctx context.Context, options *Options) (_ *JobObject, err error) {
+	if options == nil {
+		options = &Options{}
+	}
+
+	var jobName *winapi.UnicodeString
+	if options.Name != "" {
+		jobName, err = winapi.NewUnicodeString(options.Name)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	var jobHandle windows.Handle
+	if options.UseNTVariant {
+		oa := winapi.ObjectAttributes{
+			Length:     unsafe.Sizeof(winapi.ObjectAttributes{}),
+			ObjectName: jobName,
+			Attributes: 0,
+		}
+		status := winapi.NtCreateJobObject(&jobHandle, winapi.JOB_OBJECT_ALL_ACCESS, &oa)
+		if status != 0 {
+			return nil, winapi.RtlNtStatusToDosError(status)
+		}
+	} else {
+		var jobNameBuf *uint16
+		if jobName != nil && jobName.Buffer != nil {
+			jobNameBuf = jobName.Buffer
+		}
+		jobHandle, err = windows.CreateJobObject(nil, jobNameBuf)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	defer func() {
+		if err != nil {
+			windows.Close(jobHandle)
+		}
+	}()
+
+	job := &JobObject{
+		handle: jobHandle,
+	}
+
+	// If the IOCP we'll be using to receive messages for all jobs hasn't been
+	// created, create it and start polling.
+	if options.Notifications {
+		mq, err := setupNotifications(ctx, job)
+		if err != nil {
+			return nil, err
+		}
+		job.mq = mq
+	}
+
+	if options.EnableIOTracking {
+		if err := enableIOTracking(jobHandle); err != nil {
+			return nil, err
+		}
+	}
+
+	return job, nil
+}
+
+// Open opens an existing job object with name provided in `options`. If no name is provided
+// return an error since we need to know what job object to open.
+//
+// If options.Notifications is false `PollNotifications` will return immediately with error `errNotRegistered`.
+//
+// Returns a JobObject structure and an error if there is one.
+func Open(ctx context.Context, options *Options) (_ *JobObject, err error) {
+	if options == nil || (options != nil && options.Name == "") {
+		return nil, errors.New("no job object name specified to open")
+	}
+
+	unicodeJobName, err := winapi.NewUnicodeString(options.Name)
+	if err != nil {
+		return nil, err
+	}
+
+	var jobHandle windows.Handle
+	if options != nil && options.UseNTVariant {
+		oa := winapi.ObjectAttributes{
+			Length:     unsafe.Sizeof(winapi.ObjectAttributes{}),
+			ObjectName: unicodeJobName,
+			Attributes: 0,
+		}
+		status := winapi.NtOpenJobObject(&jobHandle, winapi.JOB_OBJECT_ALL_ACCESS, &oa)
+		if status != 0 {
+			return nil, winapi.RtlNtStatusToDosError(status)
+		}
+	} else {
+		jobHandle, err = winapi.OpenJobObject(winapi.JOB_OBJECT_ALL_ACCESS, false, unicodeJobName.Buffer)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	defer func() {
+		if err != nil {
+			windows.Close(jobHandle)
+		}
+	}()
+
+	job := &JobObject{
+		handle: jobHandle,
+	}
+
+	// If the IOCP we'll be using to receive messages for all jobs hasn't been
+	// created, create it and start polling.
+	if options != nil && options.Notifications {
+		mq, err := setupNotifications(ctx, job)
+		if err != nil {
+			return nil, err
+		}
+		job.mq = mq
+	}
+
+	return job, nil
+}
+
+// helper function to setup notifications for creating/opening a job object
+func setupNotifications(ctx context.Context, job *JobObject) (*queue.MessageQueue, error) {
+	job.handleLock.RLock()
+	defer job.handleLock.RUnlock()
+
+	if job.handle == 0 {
+		return nil, ErrAlreadyClosed
+	}
+
+	ioInitOnce.Do(func() {
+		h, err := windows.CreateIoCompletionPort(windows.InvalidHandle, 0, 0, 0xffffffff)
+		if err != nil {
+			initIOErr = err
+			return
+		}
+		ioCompletionPort = h
+		go pollIOCP(ctx, h)
+	})
+
+	if initIOErr != nil {
+		return nil, initIOErr
+	}
+
+	mq := queue.NewMessageQueue()
+	jobMap.Store(uintptr(job.handle), mq)
+	if err := attachIOCP(job.handle, ioCompletionPort); err != nil {
+		jobMap.Delete(uintptr(job.handle))
+		return nil, fmt.Errorf("failed to attach job to IO completion port: %w", err)
+	}
+	return mq, nil
+}
+
+// PollNotification will poll for a job object notification. This call should only be called once
+// per job (ideally in a goroutine loop) and will block if there is not a notification ready.
+// This call will return immediately with error `ErrNotRegistered` if the job was not registered
+// to receive notifications during `Create`. Internally, messages will be queued and there
+// is no worry of messages being dropped.
+func (job *JobObject) PollNotification() (interface{}, error) {
+	if job.mq == nil {
+		return nil, ErrNotRegistered
+	}
+	return job.mq.Dequeue()
+}
+
+// UpdateProcThreadAttribute updates the passed in ProcThreadAttributeList to contain what is necessary to
+// launch a process in a job at creation time. This can be used to avoid having to call Assign() after a process
+// has already started running.
+func (job *JobObject) UpdateProcThreadAttribute(attrList *windows.ProcThreadAttributeListContainer) error {
+	job.handleLock.RLock()
+	defer job.handleLock.RUnlock()
+
+	if job.handle == 0 {
+		return ErrAlreadyClosed
+	}
+
+	if err := attrList.Update(
+		winapi.PROC_THREAD_ATTRIBUTE_JOB_LIST,
+		unsafe.Pointer(&job.handle),
+		unsafe.Sizeof(job.handle),
+	); err != nil {
+		return fmt.Errorf("failed to update proc thread attributes for job object: %w", err)
+	}
+
+	return nil
+}
+
+// Close closes the job object handle.
+func (job *JobObject) Close() error {
+	job.handleLock.Lock()
+	defer job.handleLock.Unlock()
+
+	if job.handle == 0 {
+		return ErrAlreadyClosed
+	}
+
+	if err := windows.Close(job.handle); err != nil {
+		return err
+	}
+
+	if job.mq != nil {
+		job.mq.Close()
+	}
+	// Handles now invalid so if the map entry to receive notifications for this job still
+	// exists remove it so we can stop receiving notifications.
+	if _, ok := jobMap.Load(uintptr(job.handle)); ok {
+		jobMap.Delete(uintptr(job.handle))
+	}
+
+	job.handle = 0
+	return nil
+}
+
+// Assign assigns a process to the job object.
+func (job *JobObject) Assign(pid uint32) error {
+	job.handleLock.RLock()
+	defer job.handleLock.RUnlock()
+
+	if job.handle == 0 {
+		return ErrAlreadyClosed
+	}
+
+	if pid == 0 {
+		return errors.New("invalid pid: 0")
+	}
+	hProc, err := windows.OpenProcess(winapi.PROCESS_ALL_ACCESS, true, pid)
+	if err != nil {
+		return err
+	}
+	defer windows.Close(hProc)
+	return windows.AssignProcessToJobObject(job.handle, hProc)
+}
+
+// Terminate terminates the job, essentially calls TerminateProcess on every process in the
+// job.
+func (job *JobObject) Terminate(exitCode uint32) error {
+	job.handleLock.RLock()
+	defer job.handleLock.RUnlock()
+	if job.handle == 0 {
+		return ErrAlreadyClosed
+	}
+	return windows.TerminateJobObject(job.handle, exitCode)
+}
+
+// Pids returns all of the process IDs in the job object.
+func (job *JobObject) Pids() ([]uint32, error) {
+	job.handleLock.RLock()
+	defer job.handleLock.RUnlock()
+
+	if job.handle == 0 {
+		return nil, ErrAlreadyClosed
+	}
+
+	info := winapi.JOBOBJECT_BASIC_PROCESS_ID_LIST{}
+	err := winapi.QueryInformationJobObject(
+		job.handle,
+		winapi.JobObjectBasicProcessIdList,
+		unsafe.Pointer(&info),
+		uint32(unsafe.Sizeof(info)),
+		nil,
+	)
+
+	// This is either the case where there is only one process or no processes in
+	// the job. Any other case will result in ERROR_MORE_DATA. Check if info.NumberOfProcessIdsInList
+	// is 1 and just return this, otherwise return an empty slice.
+	if err == nil {
+		if info.NumberOfProcessIdsInList == 1 {
+			return []uint32{uint32(info.ProcessIdList[0])}, nil
+		}
+		// Return empty slice instead of nil to play well with the caller of this.
+		// Do not return an error if no processes are running inside the job
+		return []uint32{}, nil
+	}
+
+	if err != winapi.ERROR_MORE_DATA {
+		return nil, fmt.Errorf("failed initial query for PIDs in job object: %w", err)
+	}
+
+	jobBasicProcessIDListSize := unsafe.Sizeof(info) + (unsafe.Sizeof(info.ProcessIdList[0]) * uintptr(info.NumberOfAssignedProcesses-1))
+	buf := make([]byte, jobBasicProcessIDListSize)
+	if err = winapi.QueryInformationJobObject(
+		job.handle,
+		winapi.JobObjectBasicProcessIdList,
+		unsafe.Pointer(&buf[0]),
+		uint32(len(buf)),
+		nil,
+	); err != nil {
+		return nil, fmt.Errorf("failed to query for PIDs in job object: %w", err)
+	}
+
+	bufInfo := (*winapi.JOBOBJECT_BASIC_PROCESS_ID_LIST)(unsafe.Pointer(&buf[0]))
+	pids := make([]uint32, bufInfo.NumberOfProcessIdsInList)
+	for i, bufPid := range bufInfo.AllPids() {
+		pids[i] = uint32(bufPid)
+	}
+	return pids, nil
+}
+
+// QueryMemoryStats gets the memory stats for the job object.
+func (job *JobObject) QueryMemoryStats() (*winapi.JOBOBJECT_MEMORY_USAGE_INFORMATION, error) {
+	job.handleLock.RLock()
+	defer job.handleLock.RUnlock()
+
+	if job.handle == 0 {
+		return nil, ErrAlreadyClosed
+	}
+
+	info := winapi.JOBOBJECT_MEMORY_USAGE_INFORMATION{}
+	if err := winapi.QueryInformationJobObject(
+		job.handle,
+		winapi.JobObjectMemoryUsageInformation,
+		unsafe.Pointer(&info),
+		uint32(unsafe.Sizeof(info)),
+		nil,
+	); err != nil {
+		return nil, fmt.Errorf("failed to query for job object memory stats: %w", err)
+	}
+	return &info, nil
+}
+
+// QueryProcessorStats gets the processor stats for the job object.
+func (job *JobObject) QueryProcessorStats() (*winapi.JOBOBJECT_BASIC_ACCOUNTING_INFORMATION, error) {
+	job.handleLock.RLock()
+	defer job.handleLock.RUnlock()
+
+	if job.handle == 0 {
+		return nil, ErrAlreadyClosed
+	}
+
+	info := winapi.JOBOBJECT_BASIC_ACCOUNTING_INFORMATION{}
+	if err := winapi.QueryInformationJobObject(
+		job.handle,
+		winapi.JobObjectBasicAccountingInformation,
+		unsafe.Pointer(&info),
+		uint32(unsafe.Sizeof(info)),
+		nil,
+	); err != nil {
+		return nil, fmt.Errorf("failed to query for job object process stats: %w", err)
+	}
+	return &info, nil
+}
+
+// QueryStorageStats gets the storage (I/O) stats for the job object. This call will error
+// if either `EnableIOTracking` wasn't set to true on creation of the job, or SetIOTracking()
+// hasn't been called since creation of the job.
+func (job *JobObject) QueryStorageStats() (*winapi.JOBOBJECT_IO_ATTRIBUTION_INFORMATION, error) {
+	job.handleLock.RLock()
+	defer job.handleLock.RUnlock()
+
+	if job.handle == 0 {
+		return nil, ErrAlreadyClosed
+	}
+
+	info := winapi.JOBOBJECT_IO_ATTRIBUTION_INFORMATION{
+		ControlFlags: winapi.JOBOBJECT_IO_ATTRIBUTION_CONTROL_ENABLE,
+	}
+	if err := winapi.QueryInformationJobObject(
+		job.handle,
+		winapi.JobObjectIoAttribution,
+		unsafe.Pointer(&info),
+		uint32(unsafe.Sizeof(info)),
+		nil,
+	); err != nil {
+		return nil, fmt.Errorf("failed to query for job object storage stats: %w", err)
+	}
+	return &info, nil
+}
+
+// QueryPrivateWorkingSet returns the private working set size for the job. This is calculated by adding up the
+// private working set for every process running in the job.
+func (job *JobObject) QueryPrivateWorkingSet() (uint64, error) {
+	pids, err := job.Pids()
+	if err != nil {
+		return 0, err
+	}
+
+	openAndQueryWorkingSet := func(pid uint32) (uint64, error) {
+		h, err := windows.OpenProcess(windows.PROCESS_QUERY_LIMITED_INFORMATION, false, pid)
+		if err != nil {
+			// Continue to the next if OpenProcess doesn't return a valid handle (fails). Handles a
+			// case where one of the pids in the job exited before we open.
+			return 0, nil
+		}
+		defer func() {
+			_ = windows.Close(h)
+		}()
+		// Check if the process is actually running in the job still. There's a small chance
+		// that the process could have exited and had its pid re-used between grabbing the pids
+		// in the job and opening the handle to it above.
+		var inJob int32
+		if err := winapi.IsProcessInJob(h, job.handle, &inJob); err != nil {
+			// This shouldn't fail unless we have incorrect access rights which we control
+			// here so probably best to error out if this failed.
+			return 0, err
+		}
+		// Don't report stats for this process as it's not running in the job. This shouldn't be
+		// an error condition though.
+		if inJob == 0 {
+			return 0, nil
+		}
+
+		var vmCounters winapi.VM_COUNTERS_EX2
+		status := winapi.NtQueryInformationProcess(
+			h,
+			winapi.ProcessVmCounters,
+			unsafe.Pointer(&vmCounters),
+			uint32(unsafe.Sizeof(vmCounters)),
+			nil,
+		)
+		if !winapi.NTSuccess(status) {
+			return 0, fmt.Errorf("failed to query information for process: %w", winapi.RtlNtStatusToDosError(status))
+		}
+		return uint64(vmCounters.PrivateWorkingSetSize), nil
+	}
+
+	var jobWorkingSetSize uint64
+	for _, pid := range pids {
+		workingSet, err := openAndQueryWorkingSet(pid)
+		if err != nil {
+			return 0, err
+		}
+		jobWorkingSetSize += workingSet
+	}
+
+	return jobWorkingSetSize, nil
+}
+
+// SetIOTracking enables IO tracking for processes in the job object.
+// This enables use of the QueryStorageStats method.
+func (job *JobObject) SetIOTracking() error {
+	job.handleLock.RLock()
+	defer job.handleLock.RUnlock()
+
+	if job.handle == 0 {
+		return ErrAlreadyClosed
+	}
+
+	return enableIOTracking(job.handle)
+}
+
+func enableIOTracking(job windows.Handle) error {
+	info := winapi.JOBOBJECT_IO_ATTRIBUTION_INFORMATION{
+		ControlFlags: winapi.JOBOBJECT_IO_ATTRIBUTION_CONTROL_ENABLE,
+	}
+	if _, err := windows.SetInformationJobObject(
+		job,
+		winapi.JobObjectIoAttribution,
+		uintptr(unsafe.Pointer(&info)),
+		uint32(unsafe.Sizeof(info)),
+	); err != nil {
+		return fmt.Errorf("failed to enable IO tracking on job object: %w", err)
+	}
+	return nil
+}

vendor/github.com/Microsoft/hcsshim/internal/jobobject/limits.go

@@ -0,0 +1,315 @@
+package jobobject
+
+import (
+	"errors"
+	"fmt"
+	"unsafe"
+
+	"github.com/Microsoft/hcsshim/internal/winapi"
+	"golang.org/x/sys/windows"
+)
+
+const (
+	memoryLimitMax uint64 = 0xffffffffffffffff
+)
+
+func isFlagSet(flag, controlFlags uint32) bool {
+	return (flag & controlFlags) == flag
+}
+
+// SetResourceLimits sets resource limits on the job object (cpu, memory, storage).
+func (job *JobObject) SetResourceLimits(limits *JobLimits) error {
+	// Go through and check what limits were specified and apply them to the job.
+	if limits.MemoryLimitInBytes != 0 {
+		if err := job.SetMemoryLimit(limits.MemoryLimitInBytes); err != nil {
+			return fmt.Errorf("failed to set job object memory limit: %w", err)
+		}
+	}
+
+	if limits.CPULimit != 0 {
+		if err := job.SetCPULimit(RateBased, limits.CPULimit); err != nil {
+			return fmt.Errorf("failed to set job object cpu limit: %w", err)
+		}
+	} else if limits.CPUWeight != 0 {
+		if err := job.SetCPULimit(WeightBased, limits.CPUWeight); err != nil {
+			return fmt.Errorf("failed to set job object cpu limit: %w", err)
+		}
+	}
+
+	if limits.MaxBandwidth != 0 || limits.MaxIOPS != 0 {
+		if err := job.SetIOLimit(limits.MaxBandwidth, limits.MaxIOPS); err != nil {
+			return fmt.Errorf("failed to set io limit on job object: %w", err)
+		}
+	}
+	return nil
+}
+
+// SetTerminateOnLastHandleClose sets the job object flag that specifies that the job should terminate
+// all processes in the job on the last open handle being closed.
+func (job *JobObject) SetTerminateOnLastHandleClose() error {
+	info, err := job.getExtendedInformation()
+	if err != nil {
+		return err
+	}
+	info.BasicLimitInformation.LimitFlags |= windows.JOB_OBJECT_LIMIT_KILL_ON_JOB_CLOSE
+	return job.setExtendedInformation(info)
+}
+
+// SetMemoryLimit sets the memory limit of the job object based on the given `memoryLimitInBytes`.
+func (job *JobObject) SetMemoryLimit(memoryLimitInBytes uint64) error {
+	if memoryLimitInBytes >= memoryLimitMax {
+		return errors.New("memory limit specified exceeds the max size")
+	}
+
+	info, err := job.getExtendedInformation()
+	if err != nil {
+		return err
+	}
+
+	info.JobMemoryLimit = uintptr(memoryLimitInBytes)
+	info.BasicLimitInformation.LimitFlags |= windows.JOB_OBJECT_LIMIT_JOB_MEMORY
+	return job.setExtendedInformation(info)
+}
+
+// GetMemoryLimit gets the memory limit in bytes of the job object.
+func (job *JobObject) GetMemoryLimit() (uint64, error) {
+	info, err := job.getExtendedInformation()
+	if err != nil {
+		return 0, err
+	}
+	return uint64(info.JobMemoryLimit), nil
+}
+
+// SetCPULimit sets the CPU limit depending on the specified `CPURateControlType` to
+// `rateControlValue` for the job object.
+func (job *JobObject) SetCPULimit(rateControlType CPURateControlType, rateControlValue uint32) error {
+	cpuInfo, err := job.getCPURateControlInformation()
+	if err != nil {
+		return err
+	}
+	switch rateControlType {
+	case WeightBased:
+		if rateControlValue < cpuWeightMin || rateControlValue > cpuWeightMax {
+			return fmt.Errorf("processor weight value of `%d` is invalid", rateControlValue)
+		}
+		cpuInfo.ControlFlags |= winapi.JOB_OBJECT_CPU_RATE_CONTROL_ENABLE | winapi.JOB_OBJECT_CPU_RATE_CONTROL_WEIGHT_BASED
+		cpuInfo.Value = rateControlValue
+	case RateBased:
+		if rateControlValue < cpuLimitMin || rateControlValue > cpuLimitMax {
+			return fmt.Errorf("processor rate of `%d` is invalid", rateControlValue)
+		}
+		cpuInfo.ControlFlags |= winapi.JOB_OBJECT_CPU_RATE_CONTROL_ENABLE | winapi.JOB_OBJECT_CPU_RATE_CONTROL_HARD_CAP
+		cpuInfo.Value = rateControlValue
+	default:
+		return errors.New("invalid job object cpu rate control type")
+	}
+	return job.setCPURateControlInfo(cpuInfo)
+}
+
+// GetCPULimit gets the cpu limits for the job object.
+// `rateControlType` is used to indicate what type of cpu limit to query for.
+func (job *JobObject) GetCPULimit(rateControlType CPURateControlType) (uint32, error) {
+	info, err := job.getCPURateControlInformation()
+	if err != nil {
+		return 0, err
+	}
+
+	if !isFlagSet(winapi.JOB_OBJECT_CPU_RATE_CONTROL_ENABLE, info.ControlFlags) {
+		return 0, errors.New("the job does not have cpu rate control enabled")
+	}
+
+	switch rateControlType {
+	case WeightBased:
+		if !isFlagSet(winapi.JOB_OBJECT_CPU_RATE_CONTROL_WEIGHT_BASED, info.ControlFlags) {
+			return 0, errors.New("cannot get cpu weight for job object without cpu weight option set")
+		}
+	case RateBased:
+		if !isFlagSet(winapi.JOB_OBJECT_CPU_RATE_CONTROL_HARD_CAP, info.ControlFlags) {
+			return 0, errors.New("cannot get cpu rate hard cap for job object without cpu rate hard cap option set")
+		}
+	default:
+		return 0, errors.New("invalid job object cpu rate control type")
+	}
+	return info.Value, nil
+}
+
+// SetCPUAffinity sets the processor affinity for the job object.
+// The affinity is passed in as a bitmask.
+func (job *JobObject) SetCPUAffinity(affinityBitMask uint64) error {
+	info, err := job.getExtendedInformation()
+	if err != nil {
+		return err
+	}
+	info.BasicLimitInformation.LimitFlags |= uint32(windows.JOB_OBJECT_LIMIT_AFFINITY)
+	info.BasicLimitInformation.Affinity = uintptr(affinityBitMask)
+	return job.setExtendedInformation(info)
+}
+
+// GetCPUAffinity gets the processor affinity for the job object.
+// The returned affinity is a bitmask.
+func (job *JobObject) GetCPUAffinity() (uint64, error) {
+	info, err := job.getExtendedInformation()
+	if err != nil {
+		return 0, err
+	}
+	return uint64(info.BasicLimitInformation.Affinity), nil
+}
+
+// SetIOLimit sets the IO limits specified on the job object.
+func (job *JobObject) SetIOLimit(maxBandwidth, maxIOPS int64) error {
+	ioInfo, err := job.getIOLimit()
+	if err != nil {
+		return err
+	}
+	ioInfo.ControlFlags |= winapi.JOB_OBJECT_IO_RATE_CONTROL_ENABLE
+	if maxBandwidth != 0 {
+		ioInfo.MaxBandwidth = maxBandwidth
+	}
+	if maxIOPS != 0 {
+		ioInfo.MaxIops = maxIOPS
+	}
+	return job.setIORateControlInfo(ioInfo)
+}
+
+// GetIOMaxBandwidthLimit gets the max bandwidth for the job object.
+func (job *JobObject) GetIOMaxBandwidthLimit() (int64, error) {
+	info, err := job.getIOLimit()
+	if err != nil {
+		return 0, err
+	}
+	return info.MaxBandwidth, nil
+}
+
+// GetIOMaxIopsLimit gets the max iops for the job object.
+func (job *JobObject) GetIOMaxIopsLimit() (int64, error) {
+	info, err := job.getIOLimit()
+	if err != nil {
+		return 0, err
+	}
+	return info.MaxIops, nil
+}
+
+// Helper function for getting a job object's extended information.
+func (job *JobObject) getExtendedInformation() (*windows.JOBOBJECT_EXTENDED_LIMIT_INFORMATION, error) {
+	job.handleLock.RLock()
+	defer job.handleLock.RUnlock()
+
+	if job.handle == 0 {
+		return nil, ErrAlreadyClosed
+	}
+
+	info := windows.JOBOBJECT_EXTENDED_LIMIT_INFORMATION{}
+	if err := winapi.QueryInformationJobObject(
+		job.handle,
+		windows.JobObjectExtendedLimitInformation,
+		unsafe.Pointer(&info),
+		uint32(unsafe.Sizeof(info)),
+		nil,
+	); err != nil {
+		return nil, fmt.Errorf("query %v returned error: %w", info, err)
+	}
+	return &info, nil
+}
+
+// Helper function for getting a job object's CPU rate control information.
+func (job *JobObject) getCPURateControlInformation() (*winapi.JOBOBJECT_CPU_RATE_CONTROL_INFORMATION, error) {
+	job.handleLock.RLock()
+	defer job.handleLock.RUnlock()
+
+	if job.handle == 0 {
+		return nil, ErrAlreadyClosed
+	}
+
+	info := winapi.JOBOBJECT_CPU_RATE_CONTROL_INFORMATION{}
+	if err := winapi.QueryInformationJobObject(
+		job.handle,
+		windows.JobObjectCpuRateControlInformation,
+		unsafe.Pointer(&info),
+		uint32(unsafe.Sizeof(info)),
+		nil,
+	); err != nil {
+		return nil, fmt.Errorf("query %v returned error: %w", info, err)
+	}
+	return &info, nil
+}
+
+// Helper function for setting a job object's extended information.
+func (job *JobObject) setExtendedInformation(info *windows.JOBOBJECT_EXTENDED_LIMIT_INFORMATION) error {
+	job.handleLock.RLock()
+	defer job.handleLock.RUnlock()
+
+	if job.handle == 0 {
+		return ErrAlreadyClosed
+	}
+
+	if _, err := windows.SetInformationJobObject(
+		job.handle,
+		windows.JobObjectExtendedLimitInformation,
+		uintptr(unsafe.Pointer(info)),
+		uint32(unsafe.Sizeof(*info)),
+	); err != nil {
+		return fmt.Errorf("failed to set Extended info %v on job object: %w", info, err)
+	}
+	return nil
+}
+
+// Helper function for querying job handle for IO limit information.
+func (job *JobObject) getIOLimit() (*winapi.JOBOBJECT_IO_RATE_CONTROL_INFORMATION, error) {
+	job.handleLock.RLock()
+	defer job.handleLock.RUnlock()
+
+	if job.handle == 0 {
+		return nil, ErrAlreadyClosed
+	}
+
+	ioInfo := &winapi.JOBOBJECT_IO_RATE_CONTROL_INFORMATION{}
+	var blockCount uint32 = 1
+
+	if _, err := winapi.QueryIoRateControlInformationJobObject(
+		job.handle,
+		nil,
+		&ioInfo,
+		&blockCount,
+	); err != nil {
+		return nil, fmt.Errorf("query %v returned error: %w", ioInfo, err)
+	}
+
+	if !isFlagSet(winapi.JOB_OBJECT_IO_RATE_CONTROL_ENABLE, ioInfo.ControlFlags) {
+		return nil, fmt.Errorf("query %v cannot get IO limits for job object without IO rate control option set", ioInfo)
+	}
+	return ioInfo, nil
+}
+
+// Helper function for setting a job object's IO rate control information.
+func (job *JobObject) setIORateControlInfo(ioInfo *winapi.JOBOBJECT_IO_RATE_CONTROL_INFORMATION) error {
+	job.handleLock.RLock()
+	defer job.handleLock.RUnlock()
+
+	if job.handle == 0 {
+		return ErrAlreadyClosed
+	}
+
+	if _, err := winapi.SetIoRateControlInformationJobObject(job.handle, ioInfo); err != nil {
+		return fmt.Errorf("failed to set IO limit info %v on job object: %w", ioInfo, err)
+	}
+	return nil
+}
+
+// Helper function for setting a job object's CPU rate control information.
+func (job *JobObject) setCPURateControlInfo(cpuInfo *winapi.JOBOBJECT_CPU_RATE_CONTROL_INFORMATION) error {
+	job.handleLock.RLock()
+	defer job.handleLock.RUnlock()
+
+	if job.handle == 0 {
+		return ErrAlreadyClosed
+	}
+	if _, err := windows.SetInformationJobObject(
+		job.handle,
+		windows.JobObjectCpuRateControlInformation,
+		uintptr(unsafe.Pointer(cpuInfo)),
+		uint32(unsafe.Sizeof(cpuInfo)),
+	); err != nil {
+		return fmt.Errorf("failed to set cpu limit info %v on job object: %w", cpuInfo, err)
+	}
+	return nil
+}

vendor/github.com/Microsoft/hcsshim/internal/queue/mq.go

@@ -0,0 +1,92 @@
+package queue
+
+import (
+	"errors"
+	"sync"
+)
+
+var ErrQueueClosed = errors.New("the queue is closed for reading and writing")
+
+// MessageQueue represents a threadsafe message queue to be used to retrieve or
+// write messages to.
+type MessageQueue struct {
+	m        *sync.RWMutex
+	c        *sync.Cond
+	messages []interface{}
+	closed   bool
+}
+
+// NewMessageQueue returns a new MessageQueue.
+func NewMessageQueue() *MessageQueue {
+	m := &sync.RWMutex{}
+	return &MessageQueue{
+		m:        m,
+		c:        sync.NewCond(m),
+		messages: []interface{}{},
+	}
+}
+
+// Enqueue writes `msg` to the queue.
+func (mq *MessageQueue) Enqueue(msg interface{}) error {
+	mq.m.Lock()
+	defer mq.m.Unlock()
+
+	if mq.closed {
+		return ErrQueueClosed
+	}
+	mq.messages = append(mq.messages, msg)
+	// Signal a waiter that there is now a value available in the queue.
+	mq.c.Signal()
+	return nil
+}
+
+// Dequeue will read a value from the queue and remove it. If the queue
+// is empty, this will block until the queue is closed or a value gets enqueued.
+func (mq *MessageQueue) Dequeue() (interface{}, error) {
+	mq.m.Lock()
+	defer mq.m.Unlock()
+
+	for !mq.closed && mq.size() == 0 {
+		mq.c.Wait()
+	}
+
+	// We got woken up, check if it's because the queue got closed.
+	if mq.closed {
+		return nil, ErrQueueClosed
+	}
+
+	val := mq.messages[0]
+	mq.messages[0] = nil
+	mq.messages = mq.messages[1:]
+	return val, nil
+}
+
+// Size returns the size of the queue.
+func (mq *MessageQueue) Size() int {
+	mq.m.RLock()
+	defer mq.m.RUnlock()
+	return mq.size()
+}
+
+// Nonexported size check to check if the queue is empty inside already locked functions.
+func (mq *MessageQueue) size() int {
+	return len(mq.messages)
+}
+
+// Close closes the queue for future writes or reads. Any attempts to read or write from the
+// queue after close will return ErrQueueClosed. This is safe to call multiple times.
+func (mq *MessageQueue) Close() {
+	mq.m.Lock()
+	defer mq.m.Unlock()
+
+	// Already closed, noop
+	if mq.closed {
+		return
+	}
+
+	mq.messages = nil
+	mq.closed = true
+	// If there's anybody currently waiting on a value from Dequeue, we need to
+	// broadcast so the read(s) can return ErrQueueClosed.
+	mq.c.Broadcast()
+}

vendor/github.com/Microsoft/hcsshim/internal/winapi/iocp.go

@@ -1,3 +0,0 @@
-package winapi
-
-//sys GetQueuedCompletionStatus(cphandle windows.Handle, qty *uint32, key *uintptr, overlapped **windows.Overlapped, timeout uint32) (err error)

vendor/github.com/Microsoft/hcsshim/internal/winapi/jobobject.go

@@ -24,7 +24,10 @@ const (
 // Access rights for creating or opening job objects.
 //
 // https://docs.microsoft.com/en-us/windows/win32/procthread/job-object-security-and-access-rights
-const JOB_OBJECT_ALL_ACCESS = 0x1F001F
+const (
+	JOB_OBJECT_QUERY      = 0x0004
+	JOB_OBJECT_ALL_ACCESS = 0x1F001F
+)
 
 // IO limit flags
 //
@@ -93,7 +96,7 @@ type JOBOBJECT_BASIC_PROCESS_ID_LIST struct {
 
 // AllPids returns all the process Ids in the job object.
 func (p *JOBOBJECT_BASIC_PROCESS_ID_LIST) AllPids() []uintptr {
-	return (*[(1 << 27) - 1]uintptr)(unsafe.Pointer(&p.ProcessIdList[0]))[:p.NumberOfProcessIdsInList]
+	return (*[(1 << 27) - 1]uintptr)(unsafe.Pointer(&p.ProcessIdList[0]))[:p.NumberOfProcessIdsInList:p.NumberOfProcessIdsInList]
 }
 
 // https://docs.microsoft.com/en-us/windows/win32/api/winnt/ns-winnt-jobobject_basic_accounting_information
@@ -162,7 +165,7 @@ type JOBOBJECT_ASSOCIATE_COMPLETION_PORT struct {
 // 		PBOOL  Result
 // );
 //
-//sys IsProcessInJob(procHandle windows.Handle, jobHandle windows.Handle, result *bool) (err error) = kernel32.IsProcessInJob
+//sys IsProcessInJob(procHandle windows.Handle, jobHandle windows.Handle, result *int32) (err error) = kernel32.IsProcessInJob
 
 // BOOL QueryInformationJobObject(
 //		HANDLE             hJob,
@@ -172,7 +175,7 @@ type JOBOBJECT_ASSOCIATE_COMPLETION_PORT struct {
 //		LPDWORD            lpReturnLength
 // );
 //
-//sys QueryInformationJobObject(jobHandle windows.Handle, infoClass uint32, jobObjectInfo uintptr, jobObjectInformationLength uint32, lpReturnLength *uint32) (err error) = kernel32.QueryInformationJobObject
+//sys QueryInformationJobObject(jobHandle windows.Handle, infoClass uint32, jobObjectInfo unsafe.Pointer, jobObjectInformationLength uint32, lpReturnLength *uint32) (err error) = kernel32.QueryInformationJobObject
 
 // HANDLE OpenJobObjectW(
 //		DWORD   dwDesiredAccess,

vendor/github.com/Microsoft/hcsshim/internal/winapi/process.go

@@ -6,3 +6,60 @@ const (
 	PROC_THREAD_ATTRIBUTE_PSEUDOCONSOLE = 0x20016
 	PROC_THREAD_ATTRIBUTE_JOB_LIST      = 0x2000D
 )
+
+// ProcessVmCounters corresponds to the _VM_COUNTERS_EX and _VM_COUNTERS_EX2 structures.
+const ProcessVmCounters = 3
+
+// __kernel_entry NTSTATUS NtQueryInformationProcess(
+// 	[in]            HANDLE           ProcessHandle,
+// 	[in]            PROCESSINFOCLASS ProcessInformationClass,
+// 	[out]           PVOID            ProcessInformation,
+// 	[in]            ULONG            ProcessInformationLength,
+// 	[out, optional] PULONG           ReturnLength
+// );
+//
+//sys NtQueryInformationProcess(processHandle windows.Handle, processInfoClass uint32, processInfo unsafe.Pointer, processInfoLength uint32, returnLength *uint32) (status uint32) = ntdll.NtQueryInformationProcess
+
+// typedef struct _VM_COUNTERS_EX
+// {
+//    SIZE_T PeakVirtualSize;
+//    SIZE_T VirtualSize;
+//    ULONG PageFaultCount;
+//    SIZE_T PeakWorkingSetSize;
+//    SIZE_T WorkingSetSize;
+//    SIZE_T QuotaPeakPagedPoolUsage;
+//    SIZE_T QuotaPagedPoolUsage;
+//    SIZE_T QuotaPeakNonPagedPoolUsage;
+//    SIZE_T QuotaNonPagedPoolUsage;
+//    SIZE_T PagefileUsage;
+//    SIZE_T PeakPagefileUsage;
+//    SIZE_T PrivateUsage;
+// } VM_COUNTERS_EX, *PVM_COUNTERS_EX;
+//
+type VM_COUNTERS_EX struct {
+	PeakVirtualSize            uintptr
+	VirtualSize                uintptr
+	PageFaultCount             uint32
+	PeakWorkingSetSize         uintptr
+	WorkingSetSize             uintptr
+	QuotaPeakPagedPoolUsage    uintptr
+	QuotaPagedPoolUsage        uintptr
+	QuotaPeakNonPagedPoolUsage uintptr
+	QuotaNonPagedPoolUsage     uintptr
+	PagefileUsage              uintptr
+	PeakPagefileUsage          uintptr
+	PrivateUsage               uintptr
+}
+
+// typedef struct _VM_COUNTERS_EX2
+// {
+//    VM_COUNTERS_EX CountersEx;
+//    SIZE_T PrivateWorkingSetSize;
+//    SIZE_T SharedCommitUsage;
+// } VM_COUNTERS_EX2, *PVM_COUNTERS_EX2;
+//
+type VM_COUNTERS_EX2 struct {
+	CountersEx            VM_COUNTERS_EX
+	PrivateWorkingSetSize uintptr
+	SharedCommitUsage     uintptr
+}

vendor/github.com/Microsoft/hcsshim/internal/winapi/system.go

@@ -12,7 +12,8 @@ const STATUS_INFO_LENGTH_MISMATCH = 0xC0000004
 // 	ULONG                    SystemInformationLength,
 // 	PULONG                   ReturnLength
 // );
-//sys NtQuerySystemInformation(systemInfoClass int, systemInformation uintptr, systemInfoLength uint32, returnLength *uint32) (status uint32) = ntdll.NtQuerySystemInformation
+//
+//sys NtQuerySystemInformation(systemInfoClass int, systemInformation unsafe.Pointer, systemInfoLength uint32, returnLength *uint32) (status uint32) = ntdll.NtQuerySystemInformation
 
 type SYSTEM_PROCESS_INFORMATION struct {
 	NextEntryOffset              uint32         // ULONG

vendor/github.com/Microsoft/hcsshim/internal/winapi/winapi.go

@@ -2,4 +2,4 @@
 // be thought of as an extension to golang.org/x/sys/windows.
 package winapi
 
-//go:generate go run ..\..\mksyscall_windows.go -output zsyscall_windows.go console.go system.go net.go path.go thread.go iocp.go jobobject.go logon.go memory.go process.go processor.go devices.go filesystem.go errors.go
+//go:generate go run ..\..\mksyscall_windows.go -output zsyscall_windows.go user.go console.go system.go net.go path.go thread.go jobobject.go logon.go memory.go process.go processor.go devices.go filesystem.go errors.go

vendor/github.com/Microsoft/hcsshim/internal/winapi/zsyscall_windows.go

@@ -50,7 +50,6 @@ var (
 	procSetJobCompartmentId                    = modiphlpapi.NewProc("SetJobCompartmentId")
 	procSearchPathW                            = modkernel32.NewProc("SearchPathW")
 	procCreateRemoteThread                     = modkernel32.NewProc("CreateRemoteThread")
-	procGetQueuedCompletionStatus              = modkernel32.NewProc("GetQueuedCompletionStatus")
 	procIsProcessInJob                         = modkernel32.NewProc("IsProcessInJob")
 	procQueryInformationJobObject              = modkernel32.NewProc("QueryInformationJobObject")
 	procOpenJobObjectW                         = modkernel32.NewProc("OpenJobObjectW")
@@ -61,6 +60,7 @@ var (
 	procLogonUserW                             = modadvapi32.NewProc("LogonUserW")
 	procLocalAlloc                             = modkernel32.NewProc("LocalAlloc")
 	procLocalFree                              = modkernel32.NewProc("LocalFree")
+	procNtQueryInformationProcess              = modntdll.NewProc("NtQueryInformationProcess")
 	procGetActiveProcessorCount                = modkernel32.NewProc("GetActiveProcessorCount")
 	procCM_Get_Device_ID_List_SizeA            = modcfgmgr32.NewProc("CM_Get_Device_ID_List_SizeA")
 	procCM_Get_Device_ID_ListA                 = modcfgmgr32.NewProc("CM_Get_Device_ID_ListA")
@@ -100,7 +100,7 @@ func resizePseudoConsole(hPc windows.Handle, size uint32) (hr error) {
 	return
 }
 
-func NtQuerySystemInformation(systemInfoClass int, systemInformation uintptr, systemInfoLength uint32, returnLength *uint32) (status uint32) {
+func NtQuerySystemInformation(systemInfoClass int, systemInformation unsafe.Pointer, systemInfoLength uint32, returnLength *uint32) (status uint32) {
 	r0, _, _ := syscall.Syscall6(procNtQuerySystemInformation.Addr(), 4, uintptr(systemInfoClass), uintptr(systemInformation), uintptr(systemInfoLength), uintptr(unsafe.Pointer(returnLength)), 0, 0)
 	status = uint32(r0)
 	return
@@ -140,19 +140,7 @@ func CreateRemoteThread(process windows.Handle, sa *windows.SecurityAttributes,
 	return
 }
 
-func GetQueuedCompletionStatus(cphandle windows.Handle, qty *uint32, key *uintptr, overlapped **windows.Overlapped, timeout uint32) (err error) {
-	r1, _, e1 := syscall.Syscall6(procGetQueuedCompletionStatus.Addr(), 5, uintptr(cphandle), uintptr(unsafe.Pointer(qty)), uintptr(unsafe.Pointer(key)), uintptr(unsafe.Pointer(overlapped)), uintptr(timeout), 0)
-	if r1 == 0 {
-		if e1 != 0 {
-			err = errnoErr(e1)
-		} else {
-			err = syscall.EINVAL
-		}
-	}
-	return
-}
-
-func IsProcessInJob(procHandle windows.Handle, jobHandle windows.Handle, result *bool) (err error) {
+func IsProcessInJob(procHandle windows.Handle, jobHandle windows.Handle, result *int32) (err error) {
 	r1, _, e1 := syscall.Syscall(procIsProcessInJob.Addr(), 3, uintptr(procHandle), uintptr(jobHandle), uintptr(unsafe.Pointer(result)))
 	if r1 == 0 {
 		if e1 != 0 {
@@ -164,7 +152,7 @@ func IsProcessInJob(procHandle windows.Handle, jobHandle windows.Handle, result
 	return
 }
 
-func QueryInformationJobObject(jobHandle windows.Handle, infoClass uint32, jobObjectInfo uintptr, jobObjectInformationLength uint32, lpReturnLength *uint32) (err error) {
+func QueryInformationJobObject(jobHandle windows.Handle, infoClass uint32, jobObjectInfo unsafe.Pointer, jobObjectInformationLength uint32, lpReturnLength *uint32) (err error) {
 	r1, _, e1 := syscall.Syscall6(procQueryInformationJobObject.Addr(), 5, uintptr(jobHandle), uintptr(infoClass), uintptr(jobObjectInfo), uintptr(jobObjectInformationLength), uintptr(unsafe.Pointer(lpReturnLength)), 0)
 	if r1 == 0 {
 		if e1 != 0 {
@@ -256,6 +244,12 @@ func LocalFree(ptr uintptr) {
 	return
 }
 
+func NtQueryInformationProcess(processHandle windows.Handle, processInfoClass uint32, processInfo unsafe.Pointer, processInfoLength uint32, returnLength *uint32) (status uint32) {
+	r0, _, _ := syscall.Syscall6(procNtQueryInformationProcess.Addr(), 5, uintptr(processHandle), uintptr(processInfoClass), uintptr(processInfo), uintptr(processInfoLength), uintptr(unsafe.Pointer(returnLength)), 0)
+	status = uint32(r0)
+	return
+}
+
 func GetActiveProcessorCount(groupNumber uint16) (amount uint32) {
 	r0, _, _ := syscall.Syscall(procGetActiveProcessorCount.Addr(), 1, uintptr(groupNumber), 0, 0)
 	amount = uint32(r0)

vendor/github.com/alexellis/arkade/LICENSE

@@ -1,9 +1,6 @@
 MIT License
 
-Copyright (c) 2019-2020 Alex Ellis
-Copyright (c) 2020 k3sup author(s)
-
-Exclusions: assets, images and logos.
+Copyright (c) 2019 Alex Ellis
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

vendor/github.com/alexellis/arkade/pkg/env/env.go

@@ -0,0 +1,44 @@
+// Copyright (c) arkade author(s) 2022. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+package env
+
+import (
+	"log"
+	"os"
+	"path"
+	"strings"
+
+	execute "github.com/alexellis/go-execute/pkg/v1"
+)
+
+// GetClientArch returns a pair of arch and os
+func GetClientArch() (arch string, os string) {
+	task := execute.ExecTask{Command: "uname", Args: []string{"-m"}, StreamStdio: false}
+	res, err := task.Execute()
+	if err != nil {
+		log.Println(err)
+	}
+
+	archResult := strings.TrimSpace(res.Stdout)
+
+	taskOS := execute.ExecTask{Command: "uname", Args: []string{"-s"}, StreamStdio: false}
+	resOS, errOS := taskOS.Execute()
+	if errOS != nil {
+		log.Println(errOS)
+	}
+
+	osResult := strings.TrimSpace(resOS.Stdout)
+
+	return archResult, osResult
+}
+
+func LocalBinary(name, subdir string) string {
+	home := os.Getenv("HOME")
+	val := path.Join(home, ".arkade/bin/")
+	if len(subdir) > 0 {
+		val = path.Join(val, subdir)
+	}
+
+	return path.Join(val, name)
+}

vendor/github.com/alexellis/k3sup/pkg/env/env.go

@@ -1,51 +0,0 @@
-package env
-
-import (
-	"log"
-	"os"
-	"path"
-	"strings"
-
-	execute "github.com/alexellis/go-execute/pkg/v1"
-)
-
-// GetClientArch returns a pair of arch and os
-func GetClientArch() (string, string) {
-	task := execute.ExecTask{
-		Command:     "uname",
-		Args:        []string{"-m"},
-		StreamStdio: false,
-	}
-
-	res, err := task.Execute()
-	if err != nil {
-		log.Println(err)
-	}
-
-	arch := strings.TrimSpace(res.Stdout)
-
-	taskOS := execute.ExecTask{
-		Command:     "uname",
-		Args:        []string{"-s"},
-		StreamStdio: false,
-	}
-
-	resOS, errOS := taskOS.Execute()
-	if errOS != nil {
-		log.Println(errOS)
-	}
-
-	os := strings.TrimSpace(resOS.Stdout)
-
-	return arch, os
-}
-
-func LocalBinary(name, subdir string) string {
-	home := os.Getenv("HOME")
-	val := path.Join(home, ".k3sup/bin/")
-	if len(subdir) > 0 {
-		val = path.Join(val, subdir)
-	}
-
-	return path.Join(val, name)
-}

vendor/github.com/beorn7/perks/LICENSE

@@ -0,0 +1,20 @@
+Copyright (C) 2013 Blake Mizerany
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

vendor/github.com/beorn7/perks/quantile/stream.go

@@ -0,0 +1,316 @@
+// Package quantile computes approximate quantiles over an unbounded data
+// stream within low memory and CPU bounds.
+//
+// A small amount of accuracy is traded to achieve the above properties.
+//
+// Multiple streams can be merged before calling Query to generate a single set
+// of results. This is meaningful when the streams represent the same type of
+// data. See Merge and Samples.
+//
+// For more detailed information about the algorithm used, see:
+//
+// Effective Computation of Biased Quantiles over Data Streams
+//
+// http://www.cs.rutgers.edu/~muthu/bquant.pdf
+package quantile
+
+import (
+	"math"
+	"sort"
+)
+
+// Sample holds an observed value and meta information for compression. JSON
+// tags have been added for convenience.
+type Sample struct {
+	Value float64 `json:",string"`
+	Width float64 `json:",string"`
+	Delta float64 `json:",string"`
+}
+
+// Samples represents a slice of samples. It implements sort.Interface.
+type Samples []Sample
+
+func (a Samples) Len() int           { return len(a) }
+func (a Samples) Less(i, j int) bool { return a[i].Value < a[j].Value }
+func (a Samples) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }
+
+type invariant func(s *stream, r float64) float64
+
+// NewLowBiased returns an initialized Stream for low-biased quantiles
+// (e.g. 0.01, 0.1, 0.5) where the needed quantiles are not known a priori, but
+// error guarantees can still be given even for the lower ranks of the data
+// distribution.
+//
+// The provided epsilon is a relative error, i.e. the true quantile of a value
+// returned by a query is guaranteed to be within (1±Epsilon)*Quantile.
+//
+// See http://www.cs.rutgers.edu/~muthu/bquant.pdf for time, space, and error
+// properties.
+func NewLowBiased(epsilon float64) *Stream {
+	ƒ := func(s *stream, r float64) float64 {
+		return 2 * epsilon * r
+	}
+	return newStream(ƒ)
+}
+
+// NewHighBiased returns an initialized Stream for high-biased quantiles
+// (e.g. 0.01, 0.1, 0.5) where the needed quantiles are not known a priori, but
+// error guarantees can still be given even for the higher ranks of the data
+// distribution.
+//
+// The provided epsilon is a relative error, i.e. the true quantile of a value
+// returned by a query is guaranteed to be within 1-(1±Epsilon)*(1-Quantile).
+//
+// See http://www.cs.rutgers.edu/~muthu/bquant.pdf for time, space, and error
+// properties.
+func NewHighBiased(epsilon float64) *Stream {
+	ƒ := func(s *stream, r float64) float64 {
+		return 2 * epsilon * (s.n - r)
+	}
+	return newStream(ƒ)
+}
+
+// NewTargeted returns an initialized Stream concerned with a particular set of
+// quantile values that are supplied a priori. Knowing these a priori reduces
+// space and computation time. The targets map maps the desired quantiles to
+// their absolute errors, i.e. the true quantile of a value returned by a query
+// is guaranteed to be within (Quantile±Epsilon).
+//
+// See http://www.cs.rutgers.edu/~muthu/bquant.pdf for time, space, and error properties.
+func NewTargeted(targetMap map[float64]float64) *Stream {
+	// Convert map to slice to avoid slow iterations on a map.
+	// ƒ is called on the hot path, so converting the map to a slice
+	// beforehand results in significant CPU savings.
+	targets := targetMapToSlice(targetMap)
+
+	ƒ := func(s *stream, r float64) float64 {
+		var m = math.MaxFloat64
+		var f float64
+		for _, t := range targets {
+			if t.quantile*s.n <= r {
+				f = (2 * t.epsilon * r) / t.quantile
+			} else {
+				f = (2 * t.epsilon * (s.n - r)) / (1 - t.quantile)
+			}
+			if f < m {
+				m = f
+			}
+		}
+		return m
+	}
+	return newStream(ƒ)
+}
+
+type target struct {
+	quantile float64
+	epsilon  float64
+}
+
+func targetMapToSlice(targetMap map[float64]float64) []target {
+	targets := make([]target, 0, len(targetMap))
+
+	for quantile, epsilon := range targetMap {
+		t := target{
+			quantile: quantile,
+			epsilon:  epsilon,
+		}
+		targets = append(targets, t)
+	}
+
+	return targets
+}
+
+// Stream computes quantiles for a stream of float64s. It is not thread-safe by
+// design. Take care when using across multiple goroutines.
+type Stream struct {
+	*stream
+	b      Samples
+	sorted bool
+}
+
+func newStream(ƒ invariant) *Stream {
+	x := &stream{ƒ: ƒ}
+	return &Stream{x, make(Samples, 0, 500), true}
+}
+
+// Insert inserts v into the stream.
+func (s *Stream) Insert(v float64) {
+	s.insert(Sample{Value: v, Width: 1})
+}
+
+func (s *Stream) insert(sample Sample) {
+	s.b = append(s.b, sample)
+	s.sorted = false
+	if len(s.b) == cap(s.b) {
+		s.flush()
+	}
+}
+
+// Query returns the computed qth percentiles value. If s was created with
+// NewTargeted, and q is not in the set of quantiles provided a priori, Query
+// will return an unspecified result.
+func (s *Stream) Query(q float64) float64 {
+	if !s.flushed() {
+		// Fast path when there hasn't been enough data for a flush;
+		// this also yields better accuracy for small sets of data.
+		l := len(s.b)
+		if l == 0 {
+			return 0
+		}
+		i := int(math.Ceil(float64(l) * q))
+		if i > 0 {
+			i -= 1
+		}
+		s.maybeSort()
+		return s.b[i].Value
+	}
+	s.flush()
+	return s.stream.query(q)
+}
+
+// Merge merges samples into the underlying streams samples. This is handy when
+// merging multiple streams from separate threads, database shards, etc.
+//
+// ATTENTION: This method is broken and does not yield correct results. The
+// underlying algorithm is not capable of merging streams correctly.
+func (s *Stream) Merge(samples Samples) {
+	sort.Sort(samples)
+	s.stream.merge(samples)
+}
+
+// Reset reinitializes and clears the list reusing the samples buffer memory.
+func (s *Stream) Reset() {
+	s.stream.reset()
+	s.b = s.b[:0]
+}
+
+// Samples returns stream samples held by s.
+func (s *Stream) Samples() Samples {
+	if !s.flushed() {
+		return s.b
+	}
+	s.flush()
+	return s.stream.samples()
+}
+
+// Count returns the total number of samples observed in the stream
+// since initialization.
+func (s *Stream) Count() int {
+	return len(s.b) + s.stream.count()
+}
+
+func (s *Stream) flush() {
+	s.maybeSort()
+	s.stream.merge(s.b)
+	s.b = s.b[:0]
+}
+
+func (s *Stream) maybeSort() {
+	if !s.sorted {
+		s.sorted = true
+		sort.Sort(s.b)
+	}
+}
+
+func (s *Stream) flushed() bool {
+	return len(s.stream.l) > 0
+}
+
+type stream struct {
+	n float64
+	l []Sample
+	ƒ invariant
+}
+
+func (s *stream) reset() {
+	s.l = s.l[:0]
+	s.n = 0
+}
+
+func (s *stream) insert(v float64) {
+	s.merge(Samples{{v, 1, 0}})
+}
+
+func (s *stream) merge(samples Samples) {
+	// TODO(beorn7): This tries to merge not only individual samples, but
+	// whole summaries. The paper doesn't mention merging summaries at
+	// all. Unittests show that the merging is inaccurate. Find out how to
+	// do merges properly.
+	var r float64
+	i := 0
+	for _, sample := range samples {
+		for ; i < len(s.l); i++ {
+			c := s.l[i]
+			if c.Value > sample.Value {
+				// Insert at position i.
+				s.l = append(s.l, Sample{})
+				copy(s.l[i+1:], s.l[i:])
+				s.l[i] = Sample{
+					sample.Value,
+					sample.Width,
+					math.Max(sample.Delta, math.Floor(s.ƒ(s, r))-1),
+					// TODO(beorn7): How to calculate delta correctly?
+				}
+				i++
+				goto inserted
+			}
+			r += c.Width
+		}
+		s.l = append(s.l, Sample{sample.Value, sample.Width, 0})
+		i++
+	inserted:
+		s.n += sample.Width
+		r += sample.Width
+	}
+	s.compress()
+}
+
+func (s *stream) count() int {
+	return int(s.n)
+}
+
+func (s *stream) query(q float64) float64 {
+	t := math.Ceil(q * s.n)
+	t += math.Ceil(s.ƒ(s, t) / 2)
+	p := s.l[0]
+	var r float64
+	for _, c := range s.l[1:] {
+		r += p.Width
+		if r+c.Width+c.Delta > t {
+			return p.Value
+		}
+		p = c
+	}
+	return p.Value
+}
+
+func (s *stream) compress() {
+	if len(s.l) < 2 {
+		return
+	}
+	x := s.l[len(s.l)-1]
+	xi := len(s.l) - 1
+	r := s.n - 1 - x.Width
+
+	for i := len(s.l) - 2; i >= 0; i-- {
+		c := s.l[i]
+		if c.Width+x.Width+x.Delta <= s.ƒ(s, r) {
+			x.Width += c.Width
+			s.l[xi] = x
+			// Remove element at i.
+			copy(s.l[i:], s.l[i+1:])
+			s.l = s.l[:len(s.l)-1]
+			xi -= 1
+		} else {
+			x = c
+			xi = i
+		}
+		r -= c.Width
+	}
+}
+
+func (s *stream) samples() Samples {
+	samples := make(Samples, len(s.l))
+	copy(samples, s.l)
+	return samples
+}

vendor/github.com/cespare/xxhash/v2/LICENSE.txt

@@ -0,0 +1,22 @@
+Copyright (c) 2016 Caleb Spare
+
+MIT License
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

vendor/github.com/cespare/xxhash/v2/README.md

@@ -0,0 +1,69 @@
+# xxhash
+
+[![Go Reference](https://pkg.go.dev/badge/github.com/cespare/xxhash/v2.svg)](https://pkg.go.dev/github.com/cespare/xxhash/v2)
+[![Test](https://github.com/cespare/xxhash/actions/workflows/test.yml/badge.svg)](https://github.com/cespare/xxhash/actions/workflows/test.yml)
+
+xxhash is a Go implementation of the 64-bit
+[xxHash](http://cyan4973.github.io/xxHash/) algorithm, XXH64. This is a
+high-quality hashing algorithm that is much faster than anything in the Go
+standard library.
+
+This package provides a straightforward API:
+
+```
+func Sum64(b []byte) uint64
+func Sum64String(s string) uint64
+type Digest struct{ ... }
+    func New() *Digest
+```
+
+The `Digest` type implements hash.Hash64. Its key methods are:
+
+```
+func (*Digest) Write([]byte) (int, error)
+func (*Digest) WriteString(string) (int, error)
+func (*Digest) Sum64() uint64
+```
+
+This implementation provides a fast pure-Go implementation and an even faster
+assembly implementation for amd64.
+
+## Compatibility
+
+This package is in a module and the latest code is in version 2 of the module.
+You need a version of Go with at least "minimal module compatibility" to use
+github.com/cespare/xxhash/v2:
+
+* 1.9.7+ for Go 1.9
+* 1.10.3+ for Go 1.10
+* Go 1.11 or later
+
+I recommend using the latest release of Go.
+
+## Benchmarks
+
+Here are some quick benchmarks comparing the pure-Go and assembly
+implementations of Sum64.
+
+| input size | purego | asm |
+| --- | --- | --- |
+| 5 B   |  979.66 MB/s |  1291.17 MB/s  |
+| 100 B | 7475.26 MB/s | 7973.40 MB/s  |
+| 4 KB  | 17573.46 MB/s | 17602.65 MB/s |
+| 10 MB | 17131.46 MB/s | 17142.16 MB/s |
+
+These numbers were generated on Ubuntu 18.04 with an Intel i7-8700K CPU using
+the following commands under Go 1.11.2:
+
+```
+$ go test -tags purego -benchtime 10s -bench '/xxhash,direct,bytes'
+$ go test -benchtime 10s -bench '/xxhash,direct,bytes'
+```
+
+## Projects using this package
+
+- [InfluxDB](https://github.com/influxdata/influxdb)
+- [Prometheus](https://github.com/prometheus/prometheus)
+- [VictoriaMetrics](https://github.com/VictoriaMetrics/VictoriaMetrics)
+- [FreeCache](https://github.com/coocood/freecache)
+- [FastCache](https://github.com/VictoriaMetrics/fastcache)

vendor/github.com/cespare/xxhash/v2/xxhash.go

@@ -0,0 +1,235 @@
+// Package xxhash implements the 64-bit variant of xxHash (XXH64) as described
+// at http://cyan4973.github.io/xxHash/.
+package xxhash
+
+import (
+	"encoding/binary"
+	"errors"
+	"math/bits"
+)
+
+const (
+	prime1 uint64 = 11400714785074694791
+	prime2 uint64 = 14029467366897019727
+	prime3 uint64 = 1609587929392839161
+	prime4 uint64 = 9650029242287828579
+	prime5 uint64 = 2870177450012600261
+)
+
+// NOTE(caleb): I'm using both consts and vars of the primes. Using consts where
+// possible in the Go code is worth a small (but measurable) performance boost
+// by avoiding some MOVQs. Vars are needed for the asm and also are useful for
+// convenience in the Go code in a few places where we need to intentionally
+// avoid constant arithmetic (e.g., v1 := prime1 + prime2 fails because the
+// result overflows a uint64).
+var (
+	prime1v = prime1
+	prime2v = prime2
+	prime3v = prime3
+	prime4v = prime4
+	prime5v = prime5
+)
+
+// Digest implements hash.Hash64.
+type Digest struct {
+	v1    uint64
+	v2    uint64
+	v3    uint64
+	v4    uint64
+	total uint64
+	mem   [32]byte
+	n     int // how much of mem is used
+}
+
+// New creates a new Digest that computes the 64-bit xxHash algorithm.
+func New() *Digest {
+	var d Digest
+	d.Reset()
+	return &d
+}
+
+// Reset clears the Digest's state so that it can be reused.
+func (d *Digest) Reset() {
+	d.v1 = prime1v + prime2
+	d.v2 = prime2
+	d.v3 = 0
+	d.v4 = -prime1v
+	d.total = 0
+	d.n = 0
+}
+
+// Size always returns 8 bytes.
+func (d *Digest) Size() int { return 8 }
+
+// BlockSize always returns 32 bytes.
+func (d *Digest) BlockSize() int { return 32 }
+
+// Write adds more data to d. It always returns len(b), nil.
+func (d *Digest) Write(b []byte) (n int, err error) {
+	n = len(b)
+	d.total += uint64(n)
+
+	if d.n+n < 32 {
+		// This new data doesn't even fill the current block.
+		copy(d.mem[d.n:], b)
+		d.n += n
+		return
+	}
+
+	if d.n > 0 {
+		// Finish off the partial block.
+		copy(d.mem[d.n:], b)
+		d.v1 = round(d.v1, u64(d.mem[0:8]))
+		d.v2 = round(d.v2, u64(d.mem[8:16]))
+		d.v3 = round(d.v3, u64(d.mem[16:24]))
+		d.v4 = round(d.v4, u64(d.mem[24:32]))
+		b = b[32-d.n:]
+		d.n = 0
+	}
+
+	if len(b) >= 32 {
+		// One or more full blocks left.
+		nw := writeBlocks(d, b)
+		b = b[nw:]
+	}
+
+	// Store any remaining partial block.
+	copy(d.mem[:], b)
+	d.n = len(b)
+
+	return
+}
+
+// Sum appends the current hash to b and returns the resulting slice.
+func (d *Digest) Sum(b []byte) []byte {
+	s := d.Sum64()
+	return append(
+		b,
+		byte(s>>56),
+		byte(s>>48),
+		byte(s>>40),
+		byte(s>>32),
+		byte(s>>24),
+		byte(s>>16),
+		byte(s>>8),
+		byte(s),
+	)
+}
+
+// Sum64 returns the current hash.
+func (d *Digest) Sum64() uint64 {
+	var h uint64
+
+	if d.total >= 32 {
+		v1, v2, v3, v4 := d.v1, d.v2, d.v3, d.v4
+		h = rol1(v1) + rol7(v2) + rol12(v3) + rol18(v4)
+		h = mergeRound(h, v1)
+		h = mergeRound(h, v2)
+		h = mergeRound(h, v3)
+		h = mergeRound(h, v4)
+	} else {
+		h = d.v3 + prime5
+	}
+
+	h += d.total
+
+	i, end := 0, d.n
+	for ; i+8 <= end; i += 8 {
+		k1 := round(0, u64(d.mem[i:i+8]))
+		h ^= k1
+		h = rol27(h)*prime1 + prime4
+	}
+	if i+4 <= end {
+		h ^= uint64(u32(d.mem[i:i+4])) * prime1
+		h = rol23(h)*prime2 + prime3
+		i += 4
+	}
+	for i < end {
+		h ^= uint64(d.mem[i]) * prime5
+		h = rol11(h) * prime1
+		i++
+	}
+
+	h ^= h >> 33
+	h *= prime2
+	h ^= h >> 29
+	h *= prime3
+	h ^= h >> 32
+
+	return h
+}
+
+const (
+	magic         = "xxh\x06"
+	marshaledSize = len(magic) + 8*5 + 32
+)
+
+// MarshalBinary implements the encoding.BinaryMarshaler interface.
+func (d *Digest) MarshalBinary() ([]byte, error) {
+	b := make([]byte, 0, marshaledSize)
+	b = append(b, magic...)
+	b = appendUint64(b, d.v1)
+	b = appendUint64(b, d.v2)
+	b = appendUint64(b, d.v3)
+	b = appendUint64(b, d.v4)
+	b = appendUint64(b, d.total)
+	b = append(b, d.mem[:d.n]...)
+	b = b[:len(b)+len(d.mem)-d.n]
+	return b, nil
+}
+
+// UnmarshalBinary implements the encoding.BinaryUnmarshaler interface.
+func (d *Digest) UnmarshalBinary(b []byte) error {
+	if len(b) < len(magic) || string(b[:len(magic)]) != magic {
+		return errors.New("xxhash: invalid hash state identifier")
+	}
+	if len(b) != marshaledSize {
+		return errors.New("xxhash: invalid hash state size")
+	}
+	b = b[len(magic):]
+	b, d.v1 = consumeUint64(b)
+	b, d.v2 = consumeUint64(b)
+	b, d.v3 = consumeUint64(b)
+	b, d.v4 = consumeUint64(b)
+	b, d.total = consumeUint64(b)
+	copy(d.mem[:], b)
+	d.n = int(d.total % uint64(len(d.mem)))
+	return nil
+}
+
+func appendUint64(b []byte, x uint64) []byte {
+	var a [8]byte
+	binary.LittleEndian.PutUint64(a[:], x)
+	return append(b, a[:]...)
+}
+
+func consumeUint64(b []byte) ([]byte, uint64) {
+	x := u64(b)
+	return b[8:], x
+}
+
+func u64(b []byte) uint64 { return binary.LittleEndian.Uint64(b) }
+func u32(b []byte) uint32 { return binary.LittleEndian.Uint32(b) }
+
+func round(acc, input uint64) uint64 {
+	acc += input * prime2
+	acc = rol31(acc)
+	acc *= prime1
+	return acc
+}
+
+func mergeRound(acc, val uint64) uint64 {
+	val = round(0, val)
+	acc ^= val
+	acc = acc*prime1 + prime4
+	return acc
+}
+
+func rol1(x uint64) uint64  { return bits.RotateLeft64(x, 1) }
+func rol7(x uint64) uint64  { return bits.RotateLeft64(x, 7) }
+func rol11(x uint64) uint64 { return bits.RotateLeft64(x, 11) }
+func rol12(x uint64) uint64 { return bits.RotateLeft64(x, 12) }
+func rol18(x uint64) uint64 { return bits.RotateLeft64(x, 18) }
+func rol23(x uint64) uint64 { return bits.RotateLeft64(x, 23) }
+func rol27(x uint64) uint64 { return bits.RotateLeft64(x, 27) }
+func rol31(x uint64) uint64 { return bits.RotateLeft64(x, 31) }

vendor/github.com/cespare/xxhash/v2/xxhash_amd64.go

@@ -0,0 +1,13 @@
+// +build !appengine
+// +build gc
+// +build !purego
+
+package xxhash
+
+// Sum64 computes the 64-bit xxHash digest of b.
+//
+//go:noescape
+func Sum64(b []byte) uint64
+
+//go:noescape
+func writeBlocks(d *Digest, b []byte) int

vendor/github.com/cespare/xxhash/v2/xxhash_amd64.s

@@ -0,0 +1,215 @@
+// +build !appengine
+// +build gc
+// +build !purego
+
+#include "textflag.h"
+
+// Register allocation:
+// AX	h
+// SI	pointer to advance through b
+// DX	n
+// BX	loop end
+// R8	v1, k1
+// R9	v2
+// R10	v3
+// R11	v4
+// R12	tmp
+// R13	prime1v
+// R14	prime2v
+// DI	prime4v
+
+// round reads from and advances the buffer pointer in SI.
+// It assumes that R13 has prime1v and R14 has prime2v.
+#define round(r) \
+	MOVQ  (SI), R12 \
+	ADDQ  $8, SI    \
+	IMULQ R14, R12  \
+	ADDQ  R12, r    \
+	ROLQ  $31, r    \
+	IMULQ R13, r
+
+// mergeRound applies a merge round on the two registers acc and val.
+// It assumes that R13 has prime1v, R14 has prime2v, and DI has prime4v.
+#define mergeRound(acc, val) \
+	IMULQ R14, val \
+	ROLQ  $31, val \
+	IMULQ R13, val \
+	XORQ  val, acc \
+	IMULQ R13, acc \
+	ADDQ  DI, acc
+
+// func Sum64(b []byte) uint64
+TEXT ·Sum64(SB), NOSPLIT, $0-32
+	// Load fixed primes.
+	MOVQ ·prime1v(SB), R13
+	MOVQ ·prime2v(SB), R14
+	MOVQ ·prime4v(SB), DI
+
+	// Load slice.
+	MOVQ b_base+0(FP), SI
+	MOVQ b_len+8(FP), DX
+	LEAQ (SI)(DX*1), BX
+
+	// The first loop limit will be len(b)-32.
+	SUBQ $32, BX
+
+	// Check whether we have at least one block.
+	CMPQ DX, $32
+	JLT  noBlocks
+
+	// Set up initial state (v1, v2, v3, v4).
+	MOVQ R13, R8
+	ADDQ R14, R8
+	MOVQ R14, R9
+	XORQ R10, R10
+	XORQ R11, R11
+	SUBQ R13, R11
+
+	// Loop until SI > BX.
+blockLoop:
+	round(R8)
+	round(R9)
+	round(R10)
+	round(R11)
+
+	CMPQ SI, BX
+	JLE  blockLoop
+
+	MOVQ R8, AX
+	ROLQ $1, AX
+	MOVQ R9, R12
+	ROLQ $7, R12
+	ADDQ R12, AX
+	MOVQ R10, R12
+	ROLQ $12, R12
+	ADDQ R12, AX
+	MOVQ R11, R12
+	ROLQ $18, R12
+	ADDQ R12, AX
+
+	mergeRound(AX, R8)
+	mergeRound(AX, R9)
+	mergeRound(AX, R10)
+	mergeRound(AX, R11)
+
+	JMP afterBlocks
+
+noBlocks:
+	MOVQ ·prime5v(SB), AX
+
+afterBlocks:
+	ADDQ DX, AX
+
+	// Right now BX has len(b)-32, and we want to loop until SI > len(b)-8.
+	ADDQ $24, BX
+
+	CMPQ SI, BX
+	JG   fourByte
+
+wordLoop:
+	// Calculate k1.
+	MOVQ  (SI), R8
+	ADDQ  $8, SI
+	IMULQ R14, R8
+	ROLQ  $31, R8
+	IMULQ R13, R8
+
+	XORQ  R8, AX
+	ROLQ  $27, AX
+	IMULQ R13, AX
+	ADDQ  DI, AX
+
+	CMPQ SI, BX
+	JLE  wordLoop
+
+fourByte:
+	ADDQ $4, BX
+	CMPQ SI, BX
+	JG   singles
+
+	MOVL  (SI), R8
+	ADDQ  $4, SI
+	IMULQ R13, R8
+	XORQ  R8, AX
+
+	ROLQ  $23, AX
+	IMULQ R14, AX
+	ADDQ  ·prime3v(SB), AX
+
+singles:
+	ADDQ $4, BX
+	CMPQ SI, BX
+	JGE  finalize
+
+singlesLoop:
+	MOVBQZX (SI), R12
+	ADDQ    $1, SI
+	IMULQ   ·prime5v(SB), R12
+	XORQ    R12, AX
+
+	ROLQ  $11, AX
+	IMULQ R13, AX
+
+	CMPQ SI, BX
+	JL   singlesLoop
+
+finalize:
+	MOVQ  AX, R12
+	SHRQ  $33, R12
+	XORQ  R12, AX
+	IMULQ R14, AX
+	MOVQ  AX, R12
+	SHRQ  $29, R12
+	XORQ  R12, AX
+	IMULQ ·prime3v(SB), AX
+	MOVQ  AX, R12
+	SHRQ  $32, R12
+	XORQ  R12, AX
+
+	MOVQ AX, ret+24(FP)
+	RET
+
+// writeBlocks uses the same registers as above except that it uses AX to store
+// the d pointer.
+
+// func writeBlocks(d *Digest, b []byte) int
+TEXT ·writeBlocks(SB), NOSPLIT, $0-40
+	// Load fixed primes needed for round.
+	MOVQ ·prime1v(SB), R13
+	MOVQ ·prime2v(SB), R14
+
+	// Load slice.
+	MOVQ b_base+8(FP), SI
+	MOVQ b_len+16(FP), DX
+	LEAQ (SI)(DX*1), BX
+	SUBQ $32, BX
+
+	// Load vN from d.
+	MOVQ d+0(FP), AX
+	MOVQ 0(AX), R8   // v1
+	MOVQ 8(AX), R9   // v2
+	MOVQ 16(AX), R10 // v3
+	MOVQ 24(AX), R11 // v4
+
+	// We don't need to check the loop condition here; this function is
+	// always called with at least one block of data to process.
+blockLoop:
+	round(R8)
+	round(R9)
+	round(R10)
+	round(R11)
+
+	CMPQ SI, BX
+	JLE  blockLoop
+
+	// Copy vN back to d.
+	MOVQ R8, 0(AX)
+	MOVQ R9, 8(AX)
+	MOVQ R10, 16(AX)
+	MOVQ R11, 24(AX)
+
+	// The number of bytes written is SI minus the old base pointer.
+	SUBQ b_base+8(FP), SI
+	MOVQ SI, ret+32(FP)
+
+	RET

vendor/github.com/cespare/xxhash/v2/xxhash_other.go

@@ -0,0 +1,76 @@
+// +build !amd64 appengine !gc purego
+
+package xxhash
+
+// Sum64 computes the 64-bit xxHash digest of b.
+func Sum64(b []byte) uint64 {
+	// A simpler version would be
+	//   d := New()
+	//   d.Write(b)
+	//   return d.Sum64()
+	// but this is faster, particularly for small inputs.
+
+	n := len(b)
+	var h uint64
+
+	if n >= 32 {
+		v1 := prime1v + prime2
+		v2 := prime2
+		v3 := uint64(0)
+		v4 := -prime1v
+		for len(b) >= 32 {
+			v1 = round(v1, u64(b[0:8:len(b)]))
+			v2 = round(v2, u64(b[8:16:len(b)]))
+			v3 = round(v3, u64(b[16:24:len(b)]))
+			v4 = round(v4, u64(b[24:32:len(b)]))
+			b = b[32:len(b):len(b)]
+		}
+		h = rol1(v1) + rol7(v2) + rol12(v3) + rol18(v4)
+		h = mergeRound(h, v1)
+		h = mergeRound(h, v2)
+		h = mergeRound(h, v3)
+		h = mergeRound(h, v4)
+	} else {
+		h = prime5
+	}
+
+	h += uint64(n)
+
+	i, end := 0, len(b)
+	for ; i+8 <= end; i += 8 {
+		k1 := round(0, u64(b[i:i+8:len(b)]))
+		h ^= k1
+		h = rol27(h)*prime1 + prime4
+	}
+	if i+4 <= end {
+		h ^= uint64(u32(b[i:i+4:len(b)])) * prime1
+		h = rol23(h)*prime2 + prime3
+		i += 4
+	}
+	for ; i < end; i++ {
+		h ^= uint64(b[i]) * prime5
+		h = rol11(h) * prime1
+	}
+
+	h ^= h >> 33
+	h *= prime2
+	h ^= h >> 29
+	h *= prime3
+	h ^= h >> 32
+
+	return h
+}
+
+func writeBlocks(d *Digest, b []byte) int {
+	v1, v2, v3, v4 := d.v1, d.v2, d.v3, d.v4
+	n := len(b)
+	for len(b) >= 32 {
+		v1 = round(v1, u64(b[0:8:len(b)]))
+		v2 = round(v2, u64(b[8:16:len(b)]))
+		v3 = round(v3, u64(b[16:24:len(b)]))
+		v4 = round(v4, u64(b[24:32:len(b)]))
+		b = b[32:len(b):len(b)]
+	}
+	d.v1, d.v2, d.v3, d.v4 = v1, v2, v3, v4
+	return n - len(b)
+}

vendor/github.com/cespare/xxhash/v2/xxhash_safe.go

@@ -0,0 +1,15 @@
+// +build appengine
+
+// This file contains the safe implementations of otherwise unsafe-using code.
+
+package xxhash
+
+// Sum64String computes the 64-bit xxHash digest of s.
+func Sum64String(s string) uint64 {
+	return Sum64([]byte(s))
+}
+
+// WriteString adds more data to d. It always returns len(s), nil.
+func (d *Digest) WriteString(s string) (n int, err error) {
+	return d.Write([]byte(s))
+}

vendor/github.com/cespare/xxhash/v2/xxhash_unsafe.go

@@ -0,0 +1,57 @@
+// +build !appengine
+
+// This file encapsulates usage of unsafe.
+// xxhash_safe.go contains the safe implementations.
+
+package xxhash
+
+import (
+	"unsafe"
+)
+
+// In the future it's possible that compiler optimizations will make these
+// XxxString functions unnecessary by realizing that calls such as
+// Sum64([]byte(s)) don't need to copy s. See https://golang.org/issue/2205.
+// If that happens, even if we keep these functions they can be replaced with
+// the trivial safe code.
+
+// NOTE: The usual way of doing an unsafe string-to-[]byte conversion is:
+//
+//   var b []byte
+//   bh := (*reflect.SliceHeader)(unsafe.Pointer(&b))
+//   bh.Data = (*reflect.StringHeader)(unsafe.Pointer(&s)).Data
+//   bh.Len = len(s)
+//   bh.Cap = len(s)
+//
+// Unfortunately, as of Go 1.15.3 the inliner's cost model assigns a high enough
+// weight to this sequence of expressions that any function that uses it will
+// not be inlined. Instead, the functions below use a different unsafe
+// conversion designed to minimize the inliner weight and allow both to be
+// inlined. There is also a test (TestInlining) which verifies that these are
+// inlined.
+//
+// See https://github.com/golang/go/issues/42739 for discussion.
+
+// Sum64String computes the 64-bit xxHash digest of s.
+// It may be faster than Sum64([]byte(s)) by avoiding a copy.
+func Sum64String(s string) uint64 {
+	b := *(*[]byte)(unsafe.Pointer(&sliceHeader{s, len(s)}))
+	return Sum64(b)
+}
+
+// WriteString adds more data to d. It always returns len(s), nil.
+// It may be faster than Write([]byte(s)) by avoiding a copy.
+func (d *Digest) WriteString(s string) (n int, err error) {
+	d.Write(*(*[]byte)(unsafe.Pointer(&sliceHeader{s, len(s)})))
+	// d.Write always returns len(s), nil.
+	// Ignoring the return output and returning these fixed values buys a
+	// savings of 6 in the inliner's cost model.
+	return len(s), nil
+}
+
+// sliceHeader is similar to reflect.SliceHeader, but it assumes that the layout
+// of the first two words is the same as the layout of a string.
+type sliceHeader struct {
+	s   string
+	cap int
+}

vendor/github.com/containerd/containerd/.mailmap

@@ -87,6 +87,7 @@ Michael Crosby <crosbymichael@gmail.com> <michael@thepasture.io>
 Michael Katsoulis <michaelkatsoulis88@gmail.com>
 Mike Brown <brownwm@us.ibm.com> <mikebrow@users.noreply.github.com>
 Mohammad Asif Siddiqui <mohammad.asif.siddiqui1@huawei.com>
+Nabeel Rana <nabeelnrana@gmail.com>
 Ng Yang <wssccc@qq.com>
 Ning Li <ning.a.li@transwarp.io>
 ningmingxiao <ning.mingxiao@zte.com.cn>
@@ -121,6 +122,7 @@ Tõnis Tiigi <tonistiigi@gmail.com>
 Wade Lee <weidonglee27@gmail.com>
 Wade Lee <weidonglee27@gmail.com> <weidonglee29@gmail.com>
 Wade Lee <weidonglee27@gmail.com> <21621232@zju.edu.cn>
+Wang Bing <wangbing.adam@gmail.com>
 wanglei <wllenyj@linux.alibaba.com>
 wanglei <wllenyj@linux.alibaba.com> <wanglei01@alibaba-inc.com>
 wangzhan <wang.zhan@smartx.com>

vendor/github.com/containerd/containerd/Vagrantfile

@@ -15,9 +15,10 @@
 #   See the License for the specific language governing permissions and
 #   limitations under the License.
 
-# Vagrantfile for cgroup2 and SELinux
+# Vagrantfile for Fedora and EL
 Vagrant.configure("2") do |config|
-  config.vm.box = "fedora/35-cloud-base"
+  config.vm.box = ENV["BOX"] || "fedora/35-cloud-base"
+  config.vm.box_version = ENV["BOX_VERSION"]
   memory = 4096
   cpus = 2
   config.vm.provider :virtualbox do |v|
@@ -71,26 +72,36 @@ Vagrant.configure("2") do |config|
     SHELL
   end
 
+  # EL does not have /usr/local/{bin,sbin} in the PATH by default
+  config.vm.provision "setup-etc-environment", type: "shell", run: "once" do |sh|
+    sh.upload_path = "/tmp/vagrant-setup-etc-environment"
+    sh.inline = <<~SHELL
+        #!/usr/bin/env bash
+        set -eux -o pipefail
+        cat >> /etc/environment <<EOF
+PATH=/usr/local/go/bin:/usr/local/bin:/usr/local/sbin:$PATH
+EOF
+        source /etc/environment
+        SHELL
+  end
+
   # To re-run this provisioner, installing a different version of go:
   #   GO_VERSION="1.14.6" vagrant up --provision-with=install-golang
   #
   config.vm.provision "install-golang", type: "shell", run: "once" do |sh|
     sh.upload_path = "/tmp/vagrant-install-golang"
     sh.env = {
-        'GO_VERSION': ENV['GO_VERSION'] || "1.17.8",
+        'GO_VERSION': ENV['GO_VERSION'] || "1.17.11",
     }
     sh.inline = <<~SHELL
         #!/usr/bin/env bash
         set -eux -o pipefail
         curl -fsSL "https://dl.google.com/go/go${GO_VERSION}.linux-amd64.tar.gz" | tar Cxz /usr/local
-        cat >> /etc/environment <<EOF
-PATH=/usr/local/go/bin:$PATH
-EOF
-        source /etc/environment
         cat >> /etc/profile.d/sh.local <<EOF
 GOPATH=\\$HOME/go
 PATH=\\$GOPATH/bin:\\$PATH
 export GOPATH PATH
+git config --global --add safe.directory /vagrant
 EOF
     source /etc/profile.d/sh.local
     SHELL
@@ -218,6 +229,7 @@ EOF
         set -eux -o pipefail
         rm -rf /var/lib/containerd-test /run/containerd-test
         cd ${GOPATH}/src/github.com/containerd/containerd
+        go test -v -count=1 -race ./metrics/cgroups
         make integration EXTRA_TESTFLAGS="-timeout 15m -no-criu -test.v" TEST_RUNTIME=io.containerd.runc.v2 RUNC_FLAVOR=$RUNC_FLAVOR
     SHELL
   end
@@ -253,7 +265,7 @@ EOF
         fi
         trap cleanup EXIT
         ctr version
-        critest --parallel=$(nproc) --report-dir="${REPORT_DIR}" --ginkgo.skip='HostIpc is true'
+        critest --parallel=$[$(nproc)+2] --ginkgo.skip='HostIpc is true' --report-dir="${REPORT_DIR}"
     SHELL
   end
 

vendor/github.com/containerd/containerd/archive/tar.go

@@ -31,6 +31,7 @@ import (
 	"time"
 
 	"github.com/containerd/containerd/log"
+	"github.com/containerd/containerd/pkg/userns"
 	"github.com/containerd/continuity/fs"
 )
 
@@ -380,6 +381,10 @@ func createTarFile(ctx context.Context, path, extractDir string, hdr *tar.Header
 	// Lchown is not supported on Windows.
 	if runtime.GOOS != "windows" {
 		if err := os.Lchown(path, hdr.Uid, hdr.Gid); err != nil {
+			err = fmt.Errorf("failed to Lchown %q for UID %d, GID %d: %w", path, hdr.Uid, hdr.Gid, err)
+			if errors.Is(err, syscall.EINVAL) && userns.RunningInUserNS() {
+				err = fmt.Errorf("%w (Hint: try increasing the number of subordinate IDs in /etc/subuid and /etc/subgid)", err)
+			}
 			return err
 		}
 	}

vendor/github.com/containerd/containerd/image.go

@@ -28,6 +28,7 @@ import (
 	"github.com/containerd/containerd/diff"
 	"github.com/containerd/containerd/errdefs"
 	"github.com/containerd/containerd/images"
+	"github.com/containerd/containerd/pkg/kmutex"
 	"github.com/containerd/containerd/platforms"
 	"github.com/containerd/containerd/rootfs"
 	"github.com/containerd/containerd/snapshots"
@@ -287,6 +288,10 @@ type UnpackConfig struct {
 	// CheckPlatformSupported is whether to validate that a snapshotter
 	// supports an image's platform before unpacking
 	CheckPlatformSupported bool
+	// DuplicationSuppressor is used to make sure that there is only one
+	// in-flight fetch request or unpack handler for a given descriptor's
+	// digest or chain ID.
+	DuplicationSuppressor kmutex.KeyedLocker
 }
 
 // UnpackOpt provides configuration for unpack
@@ -300,6 +305,14 @@ func WithSnapshotterPlatformCheck() UnpackOpt {
 	}
 }
 
+// WithUnpackDuplicationSuppressor sets `DuplicationSuppressor` on the UnpackConfig.
+func WithUnpackDuplicationSuppressor(suppressor kmutex.KeyedLocker) UnpackOpt {
+	return func(ctx context.Context, uc *UnpackConfig) error {
+		uc.DuplicationSuppressor = suppressor
+		return nil
+	}
+}
+
 func (i *image) Unpack(ctx context.Context, snapshotterName string, opts ...UnpackOpt) error {
 	ctx, done, err := i.client.WithLease(ctx)
 	if err != nil {

vendor/github.com/containerd/containerd/pkg/kmutex/kmutex.go

@@ -0,0 +1,105 @@
+/*
+   Copyright The containerd Authors.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+// Package kmutex provides synchronization primitives to lock/unlock resource by unique key.
+package kmutex
+
+import (
+	"context"
+	"fmt"
+	"sync"
+
+	"golang.org/x/sync/semaphore"
+)
+
+// KeyedLocker is the interface for acquiring locks based on string.
+type KeyedLocker interface {
+	Lock(ctx context.Context, key string) error
+	Unlock(key string)
+}
+
+func New() KeyedLocker {
+	return newKeyMutex()
+}
+
+func newKeyMutex() *keyMutex {
+	return &keyMutex{
+		locks: make(map[string]*klock),
+	}
+}
+
+type keyMutex struct {
+	mu sync.Mutex
+
+	locks map[string]*klock
+}
+
+type klock struct {
+	*semaphore.Weighted
+	ref int
+}
+
+func (km *keyMutex) Lock(ctx context.Context, key string) error {
+	km.mu.Lock()
+
+	l, ok := km.locks[key]
+	if !ok {
+		km.locks[key] = &klock{
+			Weighted: semaphore.NewWeighted(1),
+		}
+		l = km.locks[key]
+	}
+	l.ref++
+	km.mu.Unlock()
+
+	if err := l.Acquire(ctx, 1); err != nil {
+		km.mu.Lock()
+		defer km.mu.Unlock()
+
+		l.ref--
+
+		if l.ref < 0 {
+			panic(fmt.Errorf("kmutex: release of unlocked key %v", key))
+		}
+
+		if l.ref == 0 {
+			delete(km.locks, key)
+		}
+		return err
+	}
+	return nil
+}
+
+func (km *keyMutex) Unlock(key string) {
+	km.mu.Lock()
+	defer km.mu.Unlock()
+
+	l, ok := km.locks[key]
+	if !ok {
+		panic(fmt.Errorf("kmutex: unlock of unlocked key %v", key))
+	}
+	l.Release(1)
+
+	l.ref--
+
+	if l.ref < 0 {
+		panic(fmt.Errorf("kmutex: released of unlocked key %v", key))
+	}
+
+	if l.ref == 0 {
+		delete(km.locks, key)
+	}
+}

vendor/github.com/containerd/containerd/pkg/kmutex/noop.go

@@ -0,0 +1,33 @@
+/*
+   Copyright The containerd Authors.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package kmutex
+
+import "context"
+
+func NewNoop() KeyedLocker {
+	return &noopMutex{}
+}
+
+type noopMutex struct {
+}
+
+func (*noopMutex) Lock(_ context.Context, _ string) error {
+	return nil
+}
+
+func (*noopMutex) Unlock(_ string) {
+}

vendor/github.com/containerd/containerd/unpacker.go

@@ -32,6 +32,7 @@ import (
 	"github.com/containerd/containerd/images"
 	"github.com/containerd/containerd/log"
 	"github.com/containerd/containerd/mount"
+	"github.com/containerd/containerd/pkg/kmutex"
 	"github.com/containerd/containerd/platforms"
 	"github.com/containerd/containerd/snapshots"
 	"github.com/opencontainers/go-digest"
@@ -59,7 +60,9 @@ func (c *Client) newUnpacker(ctx context.Context, rCtx *RemoteContext) (*unpacke
 	if err != nil {
 		return nil, err
 	}
-	var config UnpackConfig
+	var config = UnpackConfig{
+		DuplicationSuppressor: kmutex.NewNoop(),
+	}
 	for _, o := range rCtx.UnpackOpts {
 		if err := o(ctx, &config); err != nil {
 			return nil, err
@@ -127,15 +130,20 @@ func (u *unpacker) unpack(
 	ctx, cancel := context.WithCancel(ctx)
 	defer cancel()
 
-EachLayer:
-	for i, desc := range layers {
+	doUnpackFn := func(i int, desc ocispec.Descriptor) error {
 		parent := identity.ChainID(chain)
 		chain = append(chain, diffIDs[i])
-
 		chainID := identity.ChainID(chain).String()
+
+		unlock, err := u.lockSnChainID(ctx, chainID)
+		if err != nil {
+			return err
+		}
+		defer unlock()
+
 		if _, err := sn.Stat(ctx, chainID); err == nil {
 			// no need to handle
-			continue
+			return nil
 		} else if !errdefs.IsNotFound(err) {
 			return fmt.Errorf("failed to stat snapshot %s: %w", chainID, err)
 		}
@@ -167,7 +175,7 @@ EachLayer:
 						log.G(ctx).WithField("key", key).WithField("chainid", chainID).Debug("extraction snapshot already exists, chain id not found")
 					} else {
 						// no need to handle, snapshot now found with chain id
-						continue EachLayer
+						return nil
 					}
 				} else {
 					return fmt.Errorf("failed to prepare extraction snapshot %q: %w", key, err)
@@ -227,7 +235,7 @@ EachLayer:
 		if err = sn.Commit(ctx, chainID, key, opts...); err != nil {
 			abort()
 			if errdefs.IsAlreadyExists(err) {
-				continue
+				return nil
 			}
 			return fmt.Errorf("failed to commit snapshot %s: %w", key, err)
 		}
@@ -243,7 +251,13 @@ EachLayer:
 		if _, err := cs.Update(ctx, cinfo, "labels.containerd.io/uncompressed"); err != nil {
 			return err
 		}
+		return nil
+	}
 
+	for i, desc := range layers {
+		if err := doUnpackFn(i, desc); err != nil {
+			return err
+		}
 	}
 
 	chainID := identity.ChainID(chain).String()
@@ -271,17 +285,22 @@ func (u *unpacker) fetch(ctx context.Context, h images.Handler, layers []ocispec
 		desc := desc
 		i := i
 
-		if u.limiter != nil {
-			if err := u.limiter.Acquire(ctx, 1); err != nil {
-				return err
-			}
+		if err := u.acquire(ctx); err != nil {
+			return err
 		}
 
 		eg.Go(func() error {
-			_, err := h.Handle(ctx2, desc)
-			if u.limiter != nil {
-				u.limiter.Release(1)
+			unlock, err := u.lockBlobDescriptor(ctx2, desc)
+			if err != nil {
+				u.release()
+				return err
 			}
+
+			_, err = h.Handle(ctx2, desc)
+
+			unlock()
+			u.release()
+
 			if err != nil && !errors.Is(err, images.ErrSkipDesc) {
 				return err
 			}
@@ -306,7 +325,13 @@ func (u *unpacker) handlerWrapper(
 			layers = map[digest.Digest][]ocispec.Descriptor{}
 		)
 		return images.HandlerFunc(func(ctx context.Context, desc ocispec.Descriptor) ([]ocispec.Descriptor, error) {
+			unlock, err := u.lockBlobDescriptor(ctx, desc)
+			if err != nil {
+				return nil, err
+			}
+
 			children, err := f.Handle(ctx, desc)
+			unlock()
 			if err != nil {
 				return children, err
 			}
@@ -349,6 +374,50 @@ func (u *unpacker) handlerWrapper(
 	}, eg
 }
 
+func (u *unpacker) acquire(ctx context.Context) error {
+	if u.limiter == nil {
+		return nil
+	}
+	return u.limiter.Acquire(ctx, 1)
+}
+
+func (u *unpacker) release() {
+	if u.limiter == nil {
+		return
+	}
+	u.limiter.Release(1)
+}
+
+func (u *unpacker) lockSnChainID(ctx context.Context, chainID string) (func(), error) {
+	key := u.makeChainIDKeyWithSnapshotter(chainID)
+
+	if err := u.config.DuplicationSuppressor.Lock(ctx, key); err != nil {
+		return nil, err
+	}
+	return func() {
+		u.config.DuplicationSuppressor.Unlock(key)
+	}, nil
+}
+
+func (u *unpacker) lockBlobDescriptor(ctx context.Context, desc ocispec.Descriptor) (func(), error) {
+	key := u.makeBlobDescriptorKey(desc)
+
+	if err := u.config.DuplicationSuppressor.Lock(ctx, key); err != nil {
+		return nil, err
+	}
+	return func() {
+		u.config.DuplicationSuppressor.Unlock(key)
+	}, nil
+}
+
+func (u *unpacker) makeChainIDKeyWithSnapshotter(chainID string) string {
+	return fmt.Sprintf("sn://%s/%v", u.snapshotter, chainID)
+}
+
+func (u *unpacker) makeBlobDescriptorKey(desc ocispec.Descriptor) string {
+	return fmt.Sprintf("blob://%v", desc.Digest)
+}
+
 func uniquePart() string {
 	t := time.Now()
 	var b [3]byte

vendor/github.com/containerd/containerd/version/version.go

@@ -23,7 +23,7 @@ var (
 	Package = "github.com/containerd/containerd"
 
 	// Version holds the complete version number. Filled in at linking time.
-	Version = "1.6.2+unknown"
+	Version = "1.6.6+unknown"
 
 	// Revision is filled with the VCS (e.g. git) revision being used to build
 	// the program at linking time.

vendor/github.com/containerd/go-cni/.gitignore

@@ -0,0 +1,3 @@
+/bin/
+coverage.txt
+profile.out

vendor/github.com/containerd/go-cni/.golangci.yml

@@ -6,7 +6,7 @@ linters:
     - unconvert
     - gofmt
     - goimports
-    - golint
+    - revive
     - ineffassign
     - vet
     - unused

vendor/github.com/containerd/go-cni/Makefile

@@ -0,0 +1,41 @@
+#   Copyright The containerd Authors.
+
+#   Licensed under the Apache License, Version 2.0 (the "License");
+#   you may not use this file except in compliance with the License.
+#   You may obtain a copy of the License at
+
+#       http://www.apache.org/licenses/LICENSE-2.0
+
+#   Unless required by applicable law or agreed to in writing, software
+#   distributed under the License is distributed on an "AS IS" BASIS,
+#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#   See the License for the specific language governing permissions and
+#   limitations under the License.
+
+TESTFLAGS_PARALLEL ?= 8
+
+EXTRA_TESTFLAGS ?=
+
+# quiet or not
+ifeq ($(V),1)
+	Q =
+else
+	Q = @
+endif
+
+.PHONY: test integration clean help
+
+help: ## this help
+	@awk 'BEGIN {FS = ":.*?## "} /^[a-zA-Z_-]+:.*?## / {printf "\033[36m%-30s\033[0m %s\n", $$1, $$2}' $(MAKEFILE_LIST) | sort
+
+test: ## run tests, except integration tests and tests that require root
+	$(Q)go test -v -race $(EXTRA_TESTFLAGS) -count=1 ./...
+
+integration: bin/integration.test ## run integration test
+	$(Q)bin/integration.test -test.v -test.count=1 -test.root $(EXTRA_TESTFLAGS) -test.parallel $(TESTFLAGS_PARALLEL)
+
+bin/integration.test: ## build integration test binary into bin
+	$(Q)cd ./integration && go test -race -c . -o ../bin/integration.test
+
+clean: ## clean up binaries
+	$(Q)rm -rf bin/

vendor/github.com/containerd/go-cni/cni.go

@@ -33,6 +33,8 @@ import (
 type CNI interface {
 	// Setup setup the network for the namespace
 	Setup(ctx context.Context, id string, path string, opts ...NamespaceOpts) (*Result, error)
+	// SetupSerially sets up each of the network interfaces for the namespace in serial
+	SetupSerially(ctx context.Context, id string, path string, opts ...NamespaceOpts) (*Result, error)
 	// Remove tears down the network of the namespace.
 	Remove(ctx context.Context, id string, path string, opts ...NamespaceOpts) error
 	// Check checks if the network is still in desired state
@@ -165,6 +167,34 @@ func (c *libcni) Setup(ctx context.Context, id string, path string, opts ...Name
 	return c.createResult(result)
 }
 
+// SetupSerially setups the network in the namespace and returns a Result
+func (c *libcni) SetupSerially(ctx context.Context, id string, path string, opts ...NamespaceOpts) (*Result, error) {
+	if err := c.Status(); err != nil {
+		return nil, err
+	}
+	ns, err := newNamespace(id, path, opts...)
+	if err != nil {
+		return nil, err
+	}
+	result, err := c.attachNetworksSerially(ctx, ns)
+	if err != nil {
+		return nil, err
+	}
+	return c.createResult(result)
+}
+
+func (c *libcni) attachNetworksSerially(ctx context.Context, ns *Namespace) ([]*types100.Result, error) {
+	var results []*types100.Result
+	for _, network := range c.Networks() {
+		r, err := network.Attach(ctx, ns)
+		if err != nil {
+			return nil, err
+		}
+		results = append(results, r)
+	}
+	return results, nil
+}
+
 type asynchAttachResult struct {
 	index int
 	res   *types100.Result

vendor/github.com/containerd/go-cni/deprecated.go

@@ -19,10 +19,10 @@ package cni
 import types100 "github.com/containernetworking/cni/pkg/types/100"
 
 // Deprecated: use cni.Opt instead
-type CNIOpt = Opt //nolint: golint // type name will be used as cni.CNIOpt by other packages, and that stutters
+type CNIOpt = Opt //revive:disable // type name will be used as cni.CNIOpt by other packages, and that stutters
 
 // Deprecated: use cni.Result instead
-type CNIResult = Result //nolint: golint // type name will be used as cni.CNIResult by other packages, and that stutters
+type CNIResult = Result //revive:disable // type name will be used as cni.CNIResult by other packages, and that stutters
 
 // GetCNIResultFromResults creates a Result from the given slice of types100.Result,
 // adding structured data containing the interface configuration for each of the

vendor/github.com/containerd/go-cni/namespace_opts.go

@@ -18,7 +18,7 @@ package cni
 
 type NamespaceOpts func(s *Namespace) error
 
-// Capabilities
+// WithCapabilityPortMap adds support for port mappings
 func WithCapabilityPortMap(portMapping []PortMapping) NamespaceOpts {
 	return func(c *Namespace) error {
 		c.capabilityArgs["portMappings"] = portMapping
@@ -26,6 +26,7 @@ func WithCapabilityPortMap(portMapping []PortMapping) NamespaceOpts {
 	}
 }
 
+// WithCapabilityIPRanges adds support for ip ranges
 func WithCapabilityIPRanges(ipRanges []IPRanges) NamespaceOpts {
 	return func(c *Namespace) error {
 		c.capabilityArgs["ipRanges"] = ipRanges
@@ -33,8 +34,7 @@ func WithCapabilityIPRanges(ipRanges []IPRanges) NamespaceOpts {
 	}
 }
 
-// WithCapabilityBandWitdh adds support for traffic shaping:
-// https://github.com/heptio/cni-plugins/tree/master/plugins/meta/bandwidth
+// WithCapabilityBandWitdh adds support for bandwidth limits
 func WithCapabilityBandWidth(bandWidth BandWidth) NamespaceOpts {
 	return func(c *Namespace) error {
 		c.capabilityArgs["bandwidth"] = bandWidth
@@ -50,6 +50,8 @@ func WithCapabilityDNS(dns DNS) NamespaceOpts {
 	}
 }
 
+// WithCapability support well-known capabilities
+// https://www.cni.dev/docs/conventions/#well-known-capabilities
 func WithCapability(name string, capability interface{}) NamespaceOpts {
 	return func(c *Namespace) error {
 		c.capabilityArgs[name] = capability

vendor/github.com/containernetworking/cni/libcni/conf.go

@@ -21,6 +21,8 @@ import (
 	"os"
 	"path/filepath"
 	"sort"
+
+	"github.com/containernetworking/cni/pkg/types"
 )
 
 type NotFoundError struct {
@@ -41,8 +43,8 @@ func (e NoConfigsFoundError) Error() string {
 }
 
 func ConfFromBytes(bytes []byte) (*NetworkConfig, error) {
-	conf := &NetworkConfig{Bytes: bytes}
-	if err := json.Unmarshal(bytes, &conf.Network); err != nil {
+	conf := &NetworkConfig{Bytes: bytes, Network: &types.NetConf{}}
+	if err := json.Unmarshal(bytes, conf.Network); err != nil {
 		return nil, fmt.Errorf("error parsing configuration: %w", err)
 	}
 	if conf.Network.Type == "" {

vendor/github.com/containernetworking/cni/pkg/invoke/exec.go

@@ -16,6 +16,7 @@ package invoke
 
 import (
 	"context"
+	"encoding/json"
 	"fmt"
 	"os"
 
@@ -33,6 +34,43 @@ type Exec interface {
 	Decode(jsonBytes []byte) (version.PluginInfo, error)
 }
 
+// Plugin must return result in same version as specified in netconf; but
+// for backwards compatibility reasons if the result version is empty use
+// config version (rather than technically correct 0.1.0).
+// https://github.com/containernetworking/cni/issues/895
+func fixupResultVersion(netconf, result []byte) (string, []byte, error) {
+	versionDecoder := &version.ConfigDecoder{}
+	confVersion, err := versionDecoder.Decode(netconf)
+	if err != nil {
+		return "", nil, err
+	}
+
+	var rawResult map[string]interface{}
+	if err := json.Unmarshal(result, &rawResult); err != nil {
+		return "", nil, fmt.Errorf("failed to unmarshal raw result: %w", err)
+	}
+
+	// Manually decode Result version; we need to know whether its cniVersion
+	// is empty, while built-in decoders (correctly) substitute 0.1.0 for an
+	// empty version per the CNI spec.
+	if resultVerRaw, ok := rawResult["cniVersion"]; ok {
+		resultVer, ok := resultVerRaw.(string)
+		if ok && resultVer != "" {
+			return resultVer, result, nil
+		}
+	}
+
+	// If the cniVersion is not present or empty, assume the result is
+	// the same CNI spec version as the config
+	rawResult["cniVersion"] = confVersion
+	newBytes, err := json.Marshal(rawResult)
+	if err != nil {
+		return "", nil, fmt.Errorf("failed to remarshal fixed result: %w", err)
+	}
+
+	return confVersion, newBytes, nil
+}
+
 // For example, a testcase could pass an instance of the following fakeExec
 // object to ExecPluginWithResult() to verify the incoming stdin and environment
 // and provide a tailored response:
@@ -84,7 +122,12 @@ func ExecPluginWithResult(ctx context.Context, pluginPath string, netconf []byte
 		return nil, err
 	}
 
-	return create.CreateFromBytes(stdoutBytes)
+	resultVersion, fixedBytes, err := fixupResultVersion(netconf, stdoutBytes)
+	if err != nil {
+		return nil, err
+	}
+
+	return create.Create(resultVersion, fixedBytes)
 }
 
 func ExecPluginWithoutResult(ctx context.Context, pluginPath string, netconf []byte, args CNIArgs, exec Exec) error {

vendor/github.com/containernetworking/cni/pkg/version/plugin.go

@@ -86,8 +86,8 @@ func (*PluginDecoder) Decode(jsonBytes []byte) (PluginInfo, error) {
 // minor, and micro numbers or returns an error
 func ParseVersion(version string) (int, int, int, error) {
 	var major, minor, micro int
-	if version == "" {
-		return -1, -1, -1, fmt.Errorf("invalid version %q: the version is empty", version)
+	if version == "" { // special case: no version declared == v0.1.0
+		return 0, 1, 0, nil
 	}
 
 	parts := strings.Split(version, ".")

vendor/github.com/matttproud/golang_protobuf_extensions/LICENSE

@@ -0,0 +1,201 @@
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "{}"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright {yyyy} {name of copyright owner}
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.

vendor/github.com/matttproud/golang_protobuf_extensions/NOTICE

@@ -0,0 +1 @@
+Copyright 2012 Matt T. Proud (matt.proud@gmail.com)

vendor/github.com/matttproud/golang_protobuf_extensions/pbutil/.gitignore

@@ -0,0 +1 @@
+cover.dat

vendor/github.com/matttproud/golang_protobuf_extensions/pbutil/Makefile

@@ -0,0 +1,7 @@
+all:
+
+cover:
+	go test -cover -v -coverprofile=cover.dat ./...
+	go tool cover -func cover.dat
+
+.PHONY: cover

vendor/github.com/matttproud/golang_protobuf_extensions/pbutil/decode.go

@@ -0,0 +1,75 @@
+// Copyright 2013 Matt T. Proud
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package pbutil
+
+import (
+	"encoding/binary"
+	"errors"
+	"io"
+
+	"github.com/golang/protobuf/proto"
+)
+
+var errInvalidVarint = errors.New("invalid varint32 encountered")
+
+// ReadDelimited decodes a message from the provided length-delimited stream,
+// where the length is encoded as 32-bit varint prefix to the message body.
+// It returns the total number of bytes read and any applicable error.  This is
+// roughly equivalent to the companion Java API's
+// MessageLite#parseDelimitedFrom.  As per the reader contract, this function
+// calls r.Read repeatedly as required until exactly one message including its
+// prefix is read and decoded (or an error has occurred).  The function never
+// reads more bytes from the stream than required.  The function never returns
+// an error if a message has been read and decoded correctly, even if the end
+// of the stream has been reached in doing so.  In that case, any subsequent
+// calls return (0, io.EOF).
+func ReadDelimited(r io.Reader, m proto.Message) (n int, err error) {
+	// Per AbstractParser#parsePartialDelimitedFrom with
+	// CodedInputStream#readRawVarint32.
+	var headerBuf [binary.MaxVarintLen32]byte
+	var bytesRead, varIntBytes int
+	var messageLength uint64
+	for varIntBytes == 0 { // i.e. no varint has been decoded yet.
+		if bytesRead >= len(headerBuf) {
+			return bytesRead, errInvalidVarint
+		}
+		// We have to read byte by byte here to avoid reading more bytes
+		// than required. Each read byte is appended to what we have
+		// read before.
+		newBytesRead, err := r.Read(headerBuf[bytesRead : bytesRead+1])
+		if newBytesRead == 0 {
+			if err != nil {
+				return bytesRead, err
+			}
+			// A Reader should not return (0, nil), but if it does,
+			// it should be treated as no-op (according to the
+			// Reader contract). So let's go on...
+			continue
+		}
+		bytesRead += newBytesRead
+		// Now present everything read so far to the varint decoder and
+		// see if a varint can be decoded already.
+		messageLength, varIntBytes = proto.DecodeVarint(headerBuf[:bytesRead])
+	}
+
+	messageBuf := make([]byte, messageLength)
+	newBytesRead, err := io.ReadFull(r, messageBuf)
+	bytesRead += newBytesRead
+	if err != nil {
+		return bytesRead, err
+	}
+
+	return bytesRead, proto.Unmarshal(messageBuf, m)
+}

vendor/github.com/matttproud/golang_protobuf_extensions/pbutil/doc.go

@@ -0,0 +1,16 @@
+// Copyright 2013 Matt T. Proud
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package pbutil provides record length-delimited Protocol Buffer streaming.
+package pbutil

vendor/github.com/matttproud/golang_protobuf_extensions/pbutil/encode.go

@@ -0,0 +1,46 @@
+// Copyright 2013 Matt T. Proud
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package pbutil
+
+import (
+	"encoding/binary"
+	"io"
+
+	"github.com/golang/protobuf/proto"
+)
+
+// WriteDelimited encodes and dumps a message to the provided writer prefixed
+// with a 32-bit varint indicating the length of the encoded message, producing
+// a length-delimited record stream, which can be used to chain together
+// encoded messages of the same type together in a file.  It returns the total
+// number of bytes written and any applicable error.  This is roughly
+// equivalent to the companion Java API's MessageLite#writeDelimitedTo.
+func WriteDelimited(w io.Writer, m proto.Message) (n int, err error) {
+	buffer, err := proto.Marshal(m)
+	if err != nil {
+		return 0, err
+	}
+
+	var buf [binary.MaxVarintLen32]byte
+	encodedLength := binary.PutUvarint(buf[:], uint64(len(buffer)))
+
+	sync, err := w.Write(buf[:encodedLength])
+	if err != nil {
+		return sync, err
+	}
+
+	n, err = w.Write(buffer)
+	return n + sync, err
+}

vendor/github.com/opencontainers/selinux/go-selinux/rchcon.go

@@ -12,7 +12,7 @@ import (
 
 func rchcon(fpath, label string) error {
 	return pwalkdir.Walk(fpath, func(p string, _ fs.DirEntry, _ error) error {
-		e := setFileLabel(p, label)
+		e := lSetFileLabel(p, label)
 		// Walk a file tree can race with removal, so ignore ENOENT.
 		if errors.Is(e, os.ErrNotExist) {
 			return nil

vendor/github.com/opencontainers/selinux/go-selinux/rchcon_go115.go

@@ -11,7 +11,7 @@ import (
 
 func rchcon(fpath, label string) error {
 	return pwalk.Walk(fpath, func(p string, _ os.FileInfo, _ error) error {
-		e := setFileLabel(p, label)
+		e := lSetFileLabel(p, label)
 		// Walk a file tree can race with removal, so ignore ENOENT.
 		if errors.Is(e, os.ErrNotExist) {
 			return nil

vendor/github.com/openfaas/faas-provider/httputil/write_interceptor.go

@@ -0,0 +1,57 @@
+package httputil
+
+import (
+	"bufio"
+	"net"
+	"net/http"
+)
+
+func NewHttpWriteInterceptor(w http.ResponseWriter) *HttpWriteInterceptor {
+	return &HttpWriteInterceptor{w, 0}
+}
+
+type HttpWriteInterceptor struct {
+	http.ResponseWriter
+	statusCode int
+}
+
+func (c *HttpWriteInterceptor) Status() int {
+	if c.statusCode == 0 {
+		return http.StatusOK
+	}
+	return c.statusCode
+}
+
+func (c *HttpWriteInterceptor) Header() http.Header {
+	return c.ResponseWriter.Header()
+}
+
+func (c *HttpWriteInterceptor) Write(data []byte) (int, error) {
+	if c.statusCode == 0 {
+		c.WriteHeader(http.StatusOK)
+	}
+	return c.ResponseWriter.Write(data)
+}
+
+func (c *HttpWriteInterceptor) WriteHeader(code int) {
+	c.statusCode = code
+	c.ResponseWriter.WriteHeader(code)
+}
+
+func (c *HttpWriteInterceptor) Flush() {
+	fl := c.ResponseWriter.(http.Flusher)
+	fl.Flush()
+}
+
+func (c *HttpWriteInterceptor) Hijack() (net.Conn, *bufio.ReadWriter, error) {
+	hj := c.ResponseWriter.(http.Hijacker)
+	return hj.Hijack()
+}
+
+func (c *HttpWriteInterceptor) CloseNotify() <-chan bool {
+	notifier, ok := c.ResponseWriter.(http.CloseNotifier)
+	if ok == false {
+		return nil
+	}
+	return notifier.CloseNotify()
+}

vendor/github.com/openfaas/faas-provider/metrics.go

@@ -0,0 +1,72 @@
+package bootstrap
+
+import (
+	"net/http"
+	"strconv"
+	"time"
+
+	"github.com/openfaas/faas-provider/httputil"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
+)
+
+// httpMetrics is for recording R.E.D. metrics for system endpoint calls
+// for HTTP status code, method, duration and path.
+type httpMetrics struct {
+	// RequestsTotal is a Prometheus counter vector partitioned by method and status.
+	RequestsTotal *prometheus.CounterVec
+
+	// RequestDurationHistogram is a Prometheus summary vector partitioned by method and status.
+	RequestDurationHistogram *prometheus.HistogramVec
+}
+
+// newHttpMetrics initialises a new httpMetrics struct for
+// recording R.E.D. metrics for system endpoint calls
+func newHttpMetrics() *httpMetrics {
+	return &httpMetrics{
+		RequestsTotal: promauto.NewCounterVec(prometheus.CounterOpts{
+			Subsystem: "provider",
+			Name:      "http_requests_total",
+			Help:      "Total number of HTTP requests.",
+		}, []string{"code", "method", "path"}),
+		RequestDurationHistogram: promauto.NewHistogramVec(prometheus.HistogramOpts{
+			Subsystem: "provider",
+			Name:      "http_request_duration_seconds",
+			Help:      "Seconds spent serving HTTP requests.",
+			Buckets:   prometheus.DefBuckets,
+		}, []string{"code", "method", "path"}),
+	}
+}
+
+func (hm *httpMetrics) InstrumentHandler(next http.Handler, pathOverride string) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+
+		start := time.Now()
+		ww := httputil.NewHttpWriteInterceptor(w)
+		next.ServeHTTP(ww, r)
+		duration := time.Since(start)
+
+		path := r.URL.Path
+		if len(pathOverride) > 0 {
+			path = pathOverride
+		}
+
+		defer func() {
+			hm.RequestsTotal.With(
+				prometheus.Labels{"code": strconv.Itoa(ww.Status()),
+					"method": r.Method,
+					"path":   path,
+				}).
+				Inc()
+		}()
+
+		defer func() {
+			hm.RequestDurationHistogram.With(
+				prometheus.Labels{"code": strconv.Itoa(ww.Status()),
+					"method": r.Method,
+					"path":   path,
+				}).
+				Observe(duration.Seconds())
+		}()
+	}
+}

vendor/github.com/openfaas/faas-provider/serve.go

@@ -11,6 +11,8 @@ import (
 	"github.com/gorilla/mux"
 	"github.com/openfaas/faas-provider/auth"
 	"github.com/openfaas/faas-provider/types"
+
+	"github.com/prometheus/client_golang/prometheus/promhttp"
 )
 
 // NameExpression for a function / service
@@ -52,40 +54,52 @@ func Serve(handlers *types.FaaSHandlers, config *types.FaaSConfig) {
 		handlers.LogHandler = auth.DecorateWithBasicAuth(handlers.LogHandler, credentials)
 	}
 
+	hm := newHttpMetrics()
+
 	// System (auth) endpoints
-	r.HandleFunc("/system/functions", handlers.FunctionReader).Methods("GET")
-	r.HandleFunc("/system/functions", handlers.DeployHandler).Methods("POST")
-	r.HandleFunc("/system/functions", handlers.DeleteHandler).Methods("DELETE")
-	r.HandleFunc("/system/functions", handlers.UpdateHandler).Methods("PUT")
+	r.HandleFunc("/system/functions", hm.InstrumentHandler(handlers.FunctionReader, "")).Methods(http.MethodGet)
+	r.HandleFunc("/system/functions", hm.InstrumentHandler(handlers.DeployHandler, "")).Methods(http.MethodPost)
+	r.HandleFunc("/system/functions", hm.InstrumentHandler(handlers.DeleteHandler, "")).Methods(http.MethodDelete)
+	r.HandleFunc("/system/functions", hm.InstrumentHandler(handlers.UpdateHandler, "")).Methods(http.MethodPut)
 
-	r.HandleFunc("/system/function/{name:["+NameExpression+"]+}", handlers.ReplicaReader).Methods("GET")
-	r.HandleFunc("/system/scale-function/{name:["+NameExpression+"]+}", handlers.ReplicaUpdater).Methods("POST")
-	r.HandleFunc("/system/info", handlers.InfoHandler).Methods("GET")
+	r.HandleFunc("/system/function/{name:["+NameExpression+"]+}",
+		hm.InstrumentHandler(handlers.ReplicaReader, "/system/function")).Methods(http.MethodGet)
+	r.HandleFunc("/system/scale-function/{name:["+NameExpression+"]+}",
 
-	r.HandleFunc("/system/secrets", handlers.SecretHandler).Methods(http.MethodGet, http.MethodPut, http.MethodPost, http.MethodDelete)
-	r.HandleFunc("/system/logs", handlers.LogHandler).Methods(http.MethodGet)
+		hm.InstrumentHandler(handlers.ReplicaUpdater, "/system/scale-function")).Methods(http.MethodPost)
+	r.HandleFunc("/system/info",
+		hm.InstrumentHandler(handlers.InfoHandler, "")).Methods(http.MethodGet)
 
-	r.HandleFunc("/system/namespaces", handlers.ListNamespaceHandler).Methods("GET")
+	r.HandleFunc("/system/secrets",
+		hm.InstrumentHandler(handlers.SecretHandler, "")).Methods(http.MethodGet, http.MethodPut, http.MethodPost, http.MethodDelete)
+	r.HandleFunc("/system/logs",
+		hm.InstrumentHandler(handlers.LogHandler, "")).Methods(http.MethodGet)
+
+	r.HandleFunc("/system/namespaces", hm.InstrumentHandler(handlers.ListNamespaceHandler, "")).Methods(http.MethodGet)
+
+	proxyHandler := handlers.FunctionProxy
 
 	// Open endpoints
-	r.HandleFunc("/function/{name:["+NameExpression+"]+}", handlers.FunctionProxy)
-	r.HandleFunc("/function/{name:["+NameExpression+"]+}/", handlers.FunctionProxy)
-	r.HandleFunc("/function/{name:["+NameExpression+"]+}/{params:.*}", handlers.FunctionProxy)
+	r.HandleFunc("/function/{name:["+NameExpression+"]+}", proxyHandler)
+	r.HandleFunc("/function/{name:["+NameExpression+"]+}/", proxyHandler)
+	r.HandleFunc("/function/{name:["+NameExpression+"]+}/{params:.*}", proxyHandler)
 
 	if handlers.HealthHandler != nil {
-		r.HandleFunc("/healthz", handlers.HealthHandler).Methods("GET")
+		r.HandleFunc("/healthz", handlers.HealthHandler).Methods(http.MethodGet)
 	}
 
+	r.HandleFunc("/metrics", promhttp.Handler().ServeHTTP)
+
 	readTimeout := config.ReadTimeout
 	writeTimeout := config.WriteTimeout
 
-	tcpPort := 8080
+	port := 8080
 	if config.TCPPort != nil {
-		tcpPort = *config.TCPPort
+		port = *config.TCPPort
 	}
 
 	s := &http.Server{
-		Addr:           fmt.Sprintf(":%d", tcpPort),
+		Addr:           fmt.Sprintf(":%d", port),
 		ReadTimeout:    readTimeout,
 		WriteTimeout:   writeTimeout,
 		MaxHeaderBytes: http.DefaultMaxHeaderBytes, // 1MB - can be overridden by setting Server.MaxHeaderBytes.

vendor/github.com/prometheus/client_golang/LICENSE

@@ -0,0 +1,201 @@
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
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+      including but not limited to software source code, documentation
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+      "Work" shall mean the work of authorship, whether in Source or
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+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
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+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "[]"
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+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.

vendor/github.com/prometheus/client_golang/NOTICE

@@ -0,0 +1,23 @@
+Prometheus instrumentation library for Go applications
+Copyright 2012-2015 The Prometheus Authors
+
+This product includes software developed at
+SoundCloud Ltd. (http://soundcloud.com/).
+
+
+The following components are included in this product:
+
+perks - a fork of https://github.com/bmizerany/perks
+https://github.com/beorn7/perks
+Copyright 2013-2015 Blake Mizerany, Björn Rabenstein
+See https://github.com/beorn7/perks/blob/master/README.md for license details.
+
+Go support for Protocol Buffers - Google's data interchange format
+http://github.com/golang/protobuf/
+Copyright 2010 The Go Authors
+See source code for license details.
+
+Support for streaming Protocol Buffer messages for the Go language (golang).
+https://github.com/matttproud/golang_protobuf_extensions
+Copyright 2013 Matt T. Proud
+Licensed under the Apache License, Version 2.0

vendor/github.com/prometheus/client_golang/prometheus/.gitignore

@@ -0,0 +1 @@
+command-line-arguments.test

vendor/github.com/prometheus/client_golang/prometheus/README.md

@@ -0,0 +1 @@
+See [![Go Reference](https://pkg.go.dev/badge/github.com/prometheus/client_golang/prometheus.svg)](https://pkg.go.dev/github.com/prometheus/client_golang/prometheus).

vendor/github.com/prometheus/client_golang/prometheus/build_info_collector.go

@@ -0,0 +1,38 @@
+// Copyright 2021 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+import "runtime/debug"
+
+// NewBuildInfoCollector is the obsolete version of collectors.NewBuildInfoCollector.
+// See there for documentation.
+//
+// Deprecated: Use collectors.NewBuildInfoCollector instead.
+func NewBuildInfoCollector() Collector {
+	path, version, sum := "unknown", "unknown", "unknown"
+	if bi, ok := debug.ReadBuildInfo(); ok {
+		path = bi.Main.Path
+		version = bi.Main.Version
+		sum = bi.Main.Sum
+	}
+	c := &selfCollector{MustNewConstMetric(
+		NewDesc(
+			"go_build_info",
+			"Build information about the main Go module.",
+			nil, Labels{"path": path, "version": version, "checksum": sum},
+		),
+		GaugeValue, 1)}
+	c.init(c.self)
+	return c
+}

vendor/github.com/prometheus/client_golang/prometheus/collector.go

@@ -0,0 +1,128 @@
+// Copyright 2014 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+// Collector is the interface implemented by anything that can be used by
+// Prometheus to collect metrics. A Collector has to be registered for
+// collection. See Registerer.Register.
+//
+// The stock metrics provided by this package (Gauge, Counter, Summary,
+// Histogram, Untyped) are also Collectors (which only ever collect one metric,
+// namely itself). An implementer of Collector may, however, collect multiple
+// metrics in a coordinated fashion and/or create metrics on the fly. Examples
+// for collectors already implemented in this library are the metric vectors
+// (i.e. collection of multiple instances of the same Metric but with different
+// label values) like GaugeVec or SummaryVec, and the ExpvarCollector.
+type Collector interface {
+	// Describe sends the super-set of all possible descriptors of metrics
+	// collected by this Collector to the provided channel and returns once
+	// the last descriptor has been sent. The sent descriptors fulfill the
+	// consistency and uniqueness requirements described in the Desc
+	// documentation.
+	//
+	// It is valid if one and the same Collector sends duplicate
+	// descriptors. Those duplicates are simply ignored. However, two
+	// different Collectors must not send duplicate descriptors.
+	//
+	// Sending no descriptor at all marks the Collector as “unchecked”,
+	// i.e. no checks will be performed at registration time, and the
+	// Collector may yield any Metric it sees fit in its Collect method.
+	//
+	// This method idempotently sends the same descriptors throughout the
+	// lifetime of the Collector. It may be called concurrently and
+	// therefore must be implemented in a concurrency safe way.
+	//
+	// If a Collector encounters an error while executing this method, it
+	// must send an invalid descriptor (created with NewInvalidDesc) to
+	// signal the error to the registry.
+	Describe(chan<- *Desc)
+	// Collect is called by the Prometheus registry when collecting
+	// metrics. The implementation sends each collected metric via the
+	// provided channel and returns once the last metric has been sent. The
+	// descriptor of each sent metric is one of those returned by Describe
+	// (unless the Collector is unchecked, see above). Returned metrics that
+	// share the same descriptor must differ in their variable label
+	// values.
+	//
+	// This method may be called concurrently and must therefore be
+	// implemented in a concurrency safe way. Blocking occurs at the expense
+	// of total performance of rendering all registered metrics. Ideally,
+	// Collector implementations support concurrent readers.
+	Collect(chan<- Metric)
+}
+
+// DescribeByCollect is a helper to implement the Describe method of a custom
+// Collector. It collects the metrics from the provided Collector and sends
+// their descriptors to the provided channel.
+//
+// If a Collector collects the same metrics throughout its lifetime, its
+// Describe method can simply be implemented as:
+//
+//   func (c customCollector) Describe(ch chan<- *Desc) {
+//   	DescribeByCollect(c, ch)
+//   }
+//
+// However, this will not work if the metrics collected change dynamically over
+// the lifetime of the Collector in a way that their combined set of descriptors
+// changes as well. The shortcut implementation will then violate the contract
+// of the Describe method. If a Collector sometimes collects no metrics at all
+// (for example vectors like CounterVec, GaugeVec, etc., which only collect
+// metrics after a metric with a fully specified label set has been accessed),
+// it might even get registered as an unchecked Collector (cf. the Register
+// method of the Registerer interface). Hence, only use this shortcut
+// implementation of Describe if you are certain to fulfill the contract.
+//
+// The Collector example demonstrates a use of DescribeByCollect.
+func DescribeByCollect(c Collector, descs chan<- *Desc) {
+	metrics := make(chan Metric)
+	go func() {
+		c.Collect(metrics)
+		close(metrics)
+	}()
+	for m := range metrics {
+		descs <- m.Desc()
+	}
+}
+
+// selfCollector implements Collector for a single Metric so that the Metric
+// collects itself. Add it as an anonymous field to a struct that implements
+// Metric, and call init with the Metric itself as an argument.
+type selfCollector struct {
+	self Metric
+}
+
+// init provides the selfCollector with a reference to the metric it is supposed
+// to collect. It is usually called within the factory function to create a
+// metric. See example.
+func (c *selfCollector) init(self Metric) {
+	c.self = self
+}
+
+// Describe implements Collector.
+func (c *selfCollector) Describe(ch chan<- *Desc) {
+	ch <- c.self.Desc()
+}
+
+// Collect implements Collector.
+func (c *selfCollector) Collect(ch chan<- Metric) {
+	ch <- c.self
+}
+
+// collectorMetric is a metric that is also a collector.
+// Because of selfCollector, most (if not all) Metrics in
+// this package are also collectors.
+type collectorMetric interface {
+	Metric
+	Collector
+}

vendor/github.com/prometheus/client_golang/prometheus/counter.go

@@ -0,0 +1,325 @@
+// Copyright 2014 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+import (
+	"errors"
+	"math"
+	"sync/atomic"
+	"time"
+
+	dto "github.com/prometheus/client_model/go"
+)
+
+// Counter is a Metric that represents a single numerical value that only ever
+// goes up. That implies that it cannot be used to count items whose number can
+// also go down, e.g. the number of currently running goroutines. Those
+// "counters" are represented by Gauges.
+//
+// A Counter is typically used to count requests served, tasks completed, errors
+// occurred, etc.
+//
+// To create Counter instances, use NewCounter.
+type Counter interface {
+	Metric
+	Collector
+
+	// Inc increments the counter by 1. Use Add to increment it by arbitrary
+	// non-negative values.
+	Inc()
+	// Add adds the given value to the counter. It panics if the value is <
+	// 0.
+	Add(float64)
+}
+
+// ExemplarAdder is implemented by Counters that offer the option of adding a
+// value to the Counter together with an exemplar. Its AddWithExemplar method
+// works like the Add method of the Counter interface but also replaces the
+// currently saved exemplar (if any) with a new one, created from the provided
+// value, the current time as timestamp, and the provided labels. Empty Labels
+// will lead to a valid (label-less) exemplar. But if Labels is nil, the current
+// exemplar is left in place. AddWithExemplar panics if the value is < 0, if any
+// of the provided labels are invalid, or if the provided labels contain more
+// than 64 runes in total.
+type ExemplarAdder interface {
+	AddWithExemplar(value float64, exemplar Labels)
+}
+
+// CounterOpts is an alias for Opts. See there for doc comments.
+type CounterOpts Opts
+
+// NewCounter creates a new Counter based on the provided CounterOpts.
+//
+// The returned implementation also implements ExemplarAdder. It is safe to
+// perform the corresponding type assertion.
+//
+// The returned implementation tracks the counter value in two separate
+// variables, a float64 and a uint64. The latter is used to track calls of the
+// Inc method and calls of the Add method with a value that can be represented
+// as a uint64. This allows atomic increments of the counter with optimal
+// performance. (It is common to have an Inc call in very hot execution paths.)
+// Both internal tracking values are added up in the Write method. This has to
+// be taken into account when it comes to precision and overflow behavior.
+func NewCounter(opts CounterOpts) Counter {
+	desc := NewDesc(
+		BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
+		opts.Help,
+		nil,
+		opts.ConstLabels,
+	)
+	result := &counter{desc: desc, labelPairs: desc.constLabelPairs, now: time.Now}
+	result.init(result) // Init self-collection.
+	return result
+}
+
+type counter struct {
+	// valBits contains the bits of the represented float64 value, while
+	// valInt stores values that are exact integers. Both have to go first
+	// in the struct to guarantee alignment for atomic operations.
+	// http://golang.org/pkg/sync/atomic/#pkg-note-BUG
+	valBits uint64
+	valInt  uint64
+
+	selfCollector
+	desc *Desc
+
+	labelPairs []*dto.LabelPair
+	exemplar   atomic.Value // Containing nil or a *dto.Exemplar.
+
+	now func() time.Time // To mock out time.Now() for testing.
+}
+
+func (c *counter) Desc() *Desc {
+	return c.desc
+}
+
+func (c *counter) Add(v float64) {
+	if v < 0 {
+		panic(errors.New("counter cannot decrease in value"))
+	}
+
+	ival := uint64(v)
+	if float64(ival) == v {
+		atomic.AddUint64(&c.valInt, ival)
+		return
+	}
+
+	for {
+		oldBits := atomic.LoadUint64(&c.valBits)
+		newBits := math.Float64bits(math.Float64frombits(oldBits) + v)
+		if atomic.CompareAndSwapUint64(&c.valBits, oldBits, newBits) {
+			return
+		}
+	}
+}
+
+func (c *counter) AddWithExemplar(v float64, e Labels) {
+	c.Add(v)
+	c.updateExemplar(v, e)
+}
+
+func (c *counter) Inc() {
+	atomic.AddUint64(&c.valInt, 1)
+}
+
+func (c *counter) get() float64 {
+	fval := math.Float64frombits(atomic.LoadUint64(&c.valBits))
+	ival := atomic.LoadUint64(&c.valInt)
+	return fval + float64(ival)
+}
+
+func (c *counter) Write(out *dto.Metric) error {
+	val := c.get()
+
+	var exemplar *dto.Exemplar
+	if e := c.exemplar.Load(); e != nil {
+		exemplar = e.(*dto.Exemplar)
+	}
+
+	return populateMetric(CounterValue, val, c.labelPairs, exemplar, out)
+}
+
+func (c *counter) updateExemplar(v float64, l Labels) {
+	if l == nil {
+		return
+	}
+	e, err := newExemplar(v, c.now(), l)
+	if err != nil {
+		panic(err)
+	}
+	c.exemplar.Store(e)
+}
+
+// CounterVec is a Collector that bundles a set of Counters that all share the
+// same Desc, but have different values for their variable labels. This is used
+// if you want to count the same thing partitioned by various dimensions
+// (e.g. number of HTTP requests, partitioned by response code and
+// method). Create instances with NewCounterVec.
+type CounterVec struct {
+	*MetricVec
+}
+
+// NewCounterVec creates a new CounterVec based on the provided CounterOpts and
+// partitioned by the given label names.
+func NewCounterVec(opts CounterOpts, labelNames []string) *CounterVec {
+	desc := NewDesc(
+		BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
+		opts.Help,
+		labelNames,
+		opts.ConstLabels,
+	)
+	return &CounterVec{
+		MetricVec: NewMetricVec(desc, func(lvs ...string) Metric {
+			if len(lvs) != len(desc.variableLabels) {
+				panic(makeInconsistentCardinalityError(desc.fqName, desc.variableLabels, lvs))
+			}
+			result := &counter{desc: desc, labelPairs: MakeLabelPairs(desc, lvs), now: time.Now}
+			result.init(result) // Init self-collection.
+			return result
+		}),
+	}
+}
+
+// GetMetricWithLabelValues returns the Counter for the given slice of label
+// values (same order as the variable labels in Desc). If that combination of
+// label values is accessed for the first time, a new Counter is created.
+//
+// It is possible to call this method without using the returned Counter to only
+// create the new Counter but leave it at its starting value 0. See also the
+// SummaryVec example.
+//
+// Keeping the Counter for later use is possible (and should be considered if
+// performance is critical), but keep in mind that Reset, DeleteLabelValues and
+// Delete can be used to delete the Counter from the CounterVec. In that case,
+// the Counter will still exist, but it will not be exported anymore, even if a
+// Counter with the same label values is created later.
+//
+// An error is returned if the number of label values is not the same as the
+// number of variable labels in Desc (minus any curried labels).
+//
+// Note that for more than one label value, this method is prone to mistakes
+// caused by an incorrect order of arguments. Consider GetMetricWith(Labels) as
+// an alternative to avoid that type of mistake. For higher label numbers, the
+// latter has a much more readable (albeit more verbose) syntax, but it comes
+// with a performance overhead (for creating and processing the Labels map).
+// See also the GaugeVec example.
+func (v *CounterVec) GetMetricWithLabelValues(lvs ...string) (Counter, error) {
+	metric, err := v.MetricVec.GetMetricWithLabelValues(lvs...)
+	if metric != nil {
+		return metric.(Counter), err
+	}
+	return nil, err
+}
+
+// GetMetricWith returns the Counter for the given Labels map (the label names
+// must match those of the variable labels in Desc). If that label map is
+// accessed for the first time, a new Counter is created. Implications of
+// creating a Counter without using it and keeping the Counter for later use are
+// the same as for GetMetricWithLabelValues.
+//
+// An error is returned if the number and names of the Labels are inconsistent
+// with those of the variable labels in Desc (minus any curried labels).
+//
+// This method is used for the same purpose as
+// GetMetricWithLabelValues(...string). See there for pros and cons of the two
+// methods.
+func (v *CounterVec) GetMetricWith(labels Labels) (Counter, error) {
+	metric, err := v.MetricVec.GetMetricWith(labels)
+	if metric != nil {
+		return metric.(Counter), err
+	}
+	return nil, err
+}
+
+// WithLabelValues works as GetMetricWithLabelValues, but panics where
+// GetMetricWithLabelValues would have returned an error. Not returning an
+// error allows shortcuts like
+//     myVec.WithLabelValues("404", "GET").Add(42)
+func (v *CounterVec) WithLabelValues(lvs ...string) Counter {
+	c, err := v.GetMetricWithLabelValues(lvs...)
+	if err != nil {
+		panic(err)
+	}
+	return c
+}
+
+// With works as GetMetricWith, but panics where GetMetricWithLabels would have
+// returned an error. Not returning an error allows shortcuts like
+//     myVec.With(prometheus.Labels{"code": "404", "method": "GET"}).Add(42)
+func (v *CounterVec) With(labels Labels) Counter {
+	c, err := v.GetMetricWith(labels)
+	if err != nil {
+		panic(err)
+	}
+	return c
+}
+
+// CurryWith returns a vector curried with the provided labels, i.e. the
+// returned vector has those labels pre-set for all labeled operations performed
+// on it. The cardinality of the curried vector is reduced accordingly. The
+// order of the remaining labels stays the same (just with the curried labels
+// taken out of the sequence – which is relevant for the
+// (GetMetric)WithLabelValues methods). It is possible to curry a curried
+// vector, but only with labels not yet used for currying before.
+//
+// The metrics contained in the CounterVec are shared between the curried and
+// uncurried vectors. They are just accessed differently. Curried and uncurried
+// vectors behave identically in terms of collection. Only one must be
+// registered with a given registry (usually the uncurried version). The Reset
+// method deletes all metrics, even if called on a curried vector.
+func (v *CounterVec) CurryWith(labels Labels) (*CounterVec, error) {
+	vec, err := v.MetricVec.CurryWith(labels)
+	if vec != nil {
+		return &CounterVec{vec}, err
+	}
+	return nil, err
+}
+
+// MustCurryWith works as CurryWith but panics where CurryWith would have
+// returned an error.
+func (v *CounterVec) MustCurryWith(labels Labels) *CounterVec {
+	vec, err := v.CurryWith(labels)
+	if err != nil {
+		panic(err)
+	}
+	return vec
+}
+
+// CounterFunc is a Counter whose value is determined at collect time by calling a
+// provided function.
+//
+// To create CounterFunc instances, use NewCounterFunc.
+type CounterFunc interface {
+	Metric
+	Collector
+}
+
+// NewCounterFunc creates a new CounterFunc based on the provided
+// CounterOpts. The value reported is determined by calling the given function
+// from within the Write method. Take into account that metric collection may
+// happen concurrently. If that results in concurrent calls to Write, like in
+// the case where a CounterFunc is directly registered with Prometheus, the
+// provided function must be concurrency-safe. The function should also honor
+// the contract for a Counter (values only go up, not down), but compliance will
+// not be checked.
+//
+// Check out the ExampleGaugeFunc examples for the similar GaugeFunc.
+func NewCounterFunc(opts CounterOpts, function func() float64) CounterFunc {
+	return newValueFunc(NewDesc(
+		BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
+		opts.Help,
+		nil,
+		opts.ConstLabels,
+	), CounterValue, function)
+}

vendor/github.com/prometheus/client_golang/prometheus/desc.go

@@ -0,0 +1,186 @@
+// Copyright 2016 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+import (
+	"errors"
+	"fmt"
+	"sort"
+	"strings"
+
+	"github.com/cespare/xxhash/v2"
+	//nolint:staticcheck // Ignore SA1019. Need to keep deprecated package for compatibility.
+	"github.com/golang/protobuf/proto"
+	"github.com/prometheus/common/model"
+
+	dto "github.com/prometheus/client_model/go"
+)
+
+// Desc is the descriptor used by every Prometheus Metric. It is essentially
+// the immutable meta-data of a Metric. The normal Metric implementations
+// included in this package manage their Desc under the hood. Users only have to
+// deal with Desc if they use advanced features like the ExpvarCollector or
+// custom Collectors and Metrics.
+//
+// Descriptors registered with the same registry have to fulfill certain
+// consistency and uniqueness criteria if they share the same fully-qualified
+// name: They must have the same help string and the same label names (aka label
+// dimensions) in each, constLabels and variableLabels, but they must differ in
+// the values of the constLabels.
+//
+// Descriptors that share the same fully-qualified names and the same label
+// values of their constLabels are considered equal.
+//
+// Use NewDesc to create new Desc instances.
+type Desc struct {
+	// fqName has been built from Namespace, Subsystem, and Name.
+	fqName string
+	// help provides some helpful information about this metric.
+	help string
+	// constLabelPairs contains precalculated DTO label pairs based on
+	// the constant labels.
+	constLabelPairs []*dto.LabelPair
+	// variableLabels contains names of labels for which the metric
+	// maintains variable values.
+	variableLabels []string
+	// id is a hash of the values of the ConstLabels and fqName. This
+	// must be unique among all registered descriptors and can therefore be
+	// used as an identifier of the descriptor.
+	id uint64
+	// dimHash is a hash of the label names (preset and variable) and the
+	// Help string. Each Desc with the same fqName must have the same
+	// dimHash.
+	dimHash uint64
+	// err is an error that occurred during construction. It is reported on
+	// registration time.
+	err error
+}
+
+// NewDesc allocates and initializes a new Desc. Errors are recorded in the Desc
+// and will be reported on registration time. variableLabels and constLabels can
+// be nil if no such labels should be set. fqName must not be empty.
+//
+// variableLabels only contain the label names. Their label values are variable
+// and therefore not part of the Desc. (They are managed within the Metric.)
+//
+// For constLabels, the label values are constant. Therefore, they are fully
+// specified in the Desc. See the Collector example for a usage pattern.
+func NewDesc(fqName, help string, variableLabels []string, constLabels Labels) *Desc {
+	d := &Desc{
+		fqName:         fqName,
+		help:           help,
+		variableLabels: variableLabels,
+	}
+	if !model.IsValidMetricName(model.LabelValue(fqName)) {
+		d.err = fmt.Errorf("%q is not a valid metric name", fqName)
+		return d
+	}
+	// labelValues contains the label values of const labels (in order of
+	// their sorted label names) plus the fqName (at position 0).
+	labelValues := make([]string, 1, len(constLabels)+1)
+	labelValues[0] = fqName
+	labelNames := make([]string, 0, len(constLabels)+len(variableLabels))
+	labelNameSet := map[string]struct{}{}
+	// First add only the const label names and sort them...
+	for labelName := range constLabels {
+		if !checkLabelName(labelName) {
+			d.err = fmt.Errorf("%q is not a valid label name for metric %q", labelName, fqName)
+			return d
+		}
+		labelNames = append(labelNames, labelName)
+		labelNameSet[labelName] = struct{}{}
+	}
+	sort.Strings(labelNames)
+	// ... so that we can now add const label values in the order of their names.
+	for _, labelName := range labelNames {
+		labelValues = append(labelValues, constLabels[labelName])
+	}
+	// Validate the const label values. They can't have a wrong cardinality, so
+	// use in len(labelValues) as expectedNumberOfValues.
+	if err := validateLabelValues(labelValues, len(labelValues)); err != nil {
+		d.err = err
+		return d
+	}
+	// Now add the variable label names, but prefix them with something that
+	// cannot be in a regular label name. That prevents matching the label
+	// dimension with a different mix between preset and variable labels.
+	for _, labelName := range variableLabels {
+		if !checkLabelName(labelName) {
+			d.err = fmt.Errorf("%q is not a valid label name for metric %q", labelName, fqName)
+			return d
+		}
+		labelNames = append(labelNames, "$"+labelName)
+		labelNameSet[labelName] = struct{}{}
+	}
+	if len(labelNames) != len(labelNameSet) {
+		d.err = errors.New("duplicate label names")
+		return d
+	}
+
+	xxh := xxhash.New()
+	for _, val := range labelValues {
+		xxh.WriteString(val)
+		xxh.Write(separatorByteSlice)
+	}
+	d.id = xxh.Sum64()
+	// Sort labelNames so that order doesn't matter for the hash.
+	sort.Strings(labelNames)
+	// Now hash together (in this order) the help string and the sorted
+	// label names.
+	xxh.Reset()
+	xxh.WriteString(help)
+	xxh.Write(separatorByteSlice)
+	for _, labelName := range labelNames {
+		xxh.WriteString(labelName)
+		xxh.Write(separatorByteSlice)
+	}
+	d.dimHash = xxh.Sum64()
+
+	d.constLabelPairs = make([]*dto.LabelPair, 0, len(constLabels))
+	for n, v := range constLabels {
+		d.constLabelPairs = append(d.constLabelPairs, &dto.LabelPair{
+			Name:  proto.String(n),
+			Value: proto.String(v),
+		})
+	}
+	sort.Sort(labelPairSorter(d.constLabelPairs))
+	return d
+}
+
+// NewInvalidDesc returns an invalid descriptor, i.e. a descriptor with the
+// provided error set. If a collector returning such a descriptor is registered,
+// registration will fail with the provided error. NewInvalidDesc can be used by
+// a Collector to signal inability to describe itself.
+func NewInvalidDesc(err error) *Desc {
+	return &Desc{
+		err: err,
+	}
+}
+
+func (d *Desc) String() string {
+	lpStrings := make([]string, 0, len(d.constLabelPairs))
+	for _, lp := range d.constLabelPairs {
+		lpStrings = append(
+			lpStrings,
+			fmt.Sprintf("%s=%q", lp.GetName(), lp.GetValue()),
+		)
+	}
+	return fmt.Sprintf(
+		"Desc{fqName: %q, help: %q, constLabels: {%s}, variableLabels: %v}",
+		d.fqName,
+		d.help,
+		strings.Join(lpStrings, ","),
+		d.variableLabels,
+	)
+}

vendor/github.com/prometheus/client_golang/prometheus/doc.go

@@ -0,0 +1,199 @@
+// Copyright 2014 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package prometheus is the core instrumentation package. It provides metrics
+// primitives to instrument code for monitoring. It also offers a registry for
+// metrics. Sub-packages allow to expose the registered metrics via HTTP
+// (package promhttp) or push them to a Pushgateway (package push). There is
+// also a sub-package promauto, which provides metrics constructors with
+// automatic registration.
+//
+// All exported functions and methods are safe to be used concurrently unless
+// specified otherwise.
+//
+// A Basic Example
+//
+// As a starting point, a very basic usage example:
+//
+//    package main
+//
+//    import (
+//    	"log"
+//    	"net/http"
+//
+//    	"github.com/prometheus/client_golang/prometheus"
+//    	"github.com/prometheus/client_golang/prometheus/promhttp"
+//    )
+//
+//    var (
+//    	cpuTemp = prometheus.NewGauge(prometheus.GaugeOpts{
+//    		Name: "cpu_temperature_celsius",
+//    		Help: "Current temperature of the CPU.",
+//    	})
+//    	hdFailures = prometheus.NewCounterVec(
+//    		prometheus.CounterOpts{
+//    			Name: "hd_errors_total",
+//    			Help: "Number of hard-disk errors.",
+//    		},
+//    		[]string{"device"},
+//    	)
+//    )
+//
+//    func init() {
+//    	// Metrics have to be registered to be exposed:
+//    	prometheus.MustRegister(cpuTemp)
+//    	prometheus.MustRegister(hdFailures)
+//    }
+//
+//    func main() {
+//    	cpuTemp.Set(65.3)
+//    	hdFailures.With(prometheus.Labels{"device":"/dev/sda"}).Inc()
+//
+//    	// The Handler function provides a default handler to expose metrics
+//    	// via an HTTP server. "/metrics" is the usual endpoint for that.
+//    	http.Handle("/metrics", promhttp.Handler())
+//    	log.Fatal(http.ListenAndServe(":8080", nil))
+//    }
+//
+//
+// This is a complete program that exports two metrics, a Gauge and a Counter,
+// the latter with a label attached to turn it into a (one-dimensional) vector.
+//
+// Metrics
+//
+// The number of exported identifiers in this package might appear a bit
+// overwhelming. However, in addition to the basic plumbing shown in the example
+// above, you only need to understand the different metric types and their
+// vector versions for basic usage. Furthermore, if you are not concerned with
+// fine-grained control of when and how to register metrics with the registry,
+// have a look at the promauto package, which will effectively allow you to
+// ignore registration altogether in simple cases.
+//
+// Above, you have already touched the Counter and the Gauge. There are two more
+// advanced metric types: the Summary and Histogram. A more thorough description
+// of those four metric types can be found in the Prometheus docs:
+// https://prometheus.io/docs/concepts/metric_types/
+//
+// In addition to the fundamental metric types Gauge, Counter, Summary, and
+// Histogram, a very important part of the Prometheus data model is the
+// partitioning of samples along dimensions called labels, which results in
+// metric vectors. The fundamental types are GaugeVec, CounterVec, SummaryVec,
+// and HistogramVec.
+//
+// While only the fundamental metric types implement the Metric interface, both
+// the metrics and their vector versions implement the Collector interface. A
+// Collector manages the collection of a number of Metrics, but for convenience,
+// a Metric can also “collect itself”. Note that Gauge, Counter, Summary, and
+// Histogram are interfaces themselves while GaugeVec, CounterVec, SummaryVec,
+// and HistogramVec are not.
+//
+// To create instances of Metrics and their vector versions, you need a suitable
+// …Opts struct, i.e. GaugeOpts, CounterOpts, SummaryOpts, or HistogramOpts.
+//
+// Custom Collectors and constant Metrics
+//
+// While you could create your own implementations of Metric, most likely you
+// will only ever implement the Collector interface on your own. At a first
+// glance, a custom Collector seems handy to bundle Metrics for common
+// registration (with the prime example of the different metric vectors above,
+// which bundle all the metrics of the same name but with different labels).
+//
+// There is a more involved use case, too: If you already have metrics
+// available, created outside of the Prometheus context, you don't need the
+// interface of the various Metric types. You essentially want to mirror the
+// existing numbers into Prometheus Metrics during collection. An own
+// implementation of the Collector interface is perfect for that. You can create
+// Metric instances “on the fly” using NewConstMetric, NewConstHistogram, and
+// NewConstSummary (and their respective Must… versions). NewConstMetric is used
+// for all metric types with just a float64 as their value: Counter, Gauge, and
+// a special “type” called Untyped. Use the latter if you are not sure if the
+// mirrored metric is a Counter or a Gauge. Creation of the Metric instance
+// happens in the Collect method. The Describe method has to return separate
+// Desc instances, representative of the “throw-away” metrics to be created
+// later.  NewDesc comes in handy to create those Desc instances. Alternatively,
+// you could return no Desc at all, which will mark the Collector “unchecked”.
+// No checks are performed at registration time, but metric consistency will
+// still be ensured at scrape time, i.e. any inconsistencies will lead to scrape
+// errors. Thus, with unchecked Collectors, the responsibility to not collect
+// metrics that lead to inconsistencies in the total scrape result lies with the
+// implementer of the Collector. While this is not a desirable state, it is
+// sometimes necessary. The typical use case is a situation where the exact
+// metrics to be returned by a Collector cannot be predicted at registration
+// time, but the implementer has sufficient knowledge of the whole system to
+// guarantee metric consistency.
+//
+// The Collector example illustrates the use case. You can also look at the
+// source code of the processCollector (mirroring process metrics), the
+// goCollector (mirroring Go metrics), or the expvarCollector (mirroring expvar
+// metrics) as examples that are used in this package itself.
+//
+// If you just need to call a function to get a single float value to collect as
+// a metric, GaugeFunc, CounterFunc, or UntypedFunc might be interesting
+// shortcuts.
+//
+// Advanced Uses of the Registry
+//
+// While MustRegister is the by far most common way of registering a Collector,
+// sometimes you might want to handle the errors the registration might cause.
+// As suggested by the name, MustRegister panics if an error occurs. With the
+// Register function, the error is returned and can be handled.
+//
+// An error is returned if the registered Collector is incompatible or
+// inconsistent with already registered metrics. The registry aims for
+// consistency of the collected metrics according to the Prometheus data model.
+// Inconsistencies are ideally detected at registration time, not at collect
+// time. The former will usually be detected at start-up time of a program,
+// while the latter will only happen at scrape time, possibly not even on the
+// first scrape if the inconsistency only becomes relevant later. That is the
+// main reason why a Collector and a Metric have to describe themselves to the
+// registry.
+//
+// So far, everything we did operated on the so-called default registry, as it
+// can be found in the global DefaultRegisterer variable. With NewRegistry, you
+// can create a custom registry, or you can even implement the Registerer or
+// Gatherer interfaces yourself. The methods Register and Unregister work in the
+// same way on a custom registry as the global functions Register and Unregister
+// on the default registry.
+//
+// There are a number of uses for custom registries: You can use registries with
+// special properties, see NewPedanticRegistry. You can avoid global state, as
+// it is imposed by the DefaultRegisterer. You can use multiple registries at
+// the same time to expose different metrics in different ways.  You can use
+// separate registries for testing purposes.
+//
+// Also note that the DefaultRegisterer comes registered with a Collector for Go
+// runtime metrics (via NewGoCollector) and a Collector for process metrics (via
+// NewProcessCollector). With a custom registry, you are in control and decide
+// yourself about the Collectors to register.
+//
+// HTTP Exposition
+//
+// The Registry implements the Gatherer interface. The caller of the Gather
+// method can then expose the gathered metrics in some way. Usually, the metrics
+// are served via HTTP on the /metrics endpoint. That's happening in the example
+// above. The tools to expose metrics via HTTP are in the promhttp sub-package.
+//
+// Pushing to the Pushgateway
+//
+// Function for pushing to the Pushgateway can be found in the push sub-package.
+//
+// Graphite Bridge
+//
+// Functions and examples to push metrics from a Gatherer to Graphite can be
+// found in the graphite sub-package.
+//
+// Other Means of Exposition
+//
+// More ways of exposing metrics can easily be added by following the approaches
+// of the existing implementations.
+package prometheus

vendor/github.com/prometheus/client_golang/prometheus/expvar_collector.go

@@ -0,0 +1,86 @@
+// Copyright 2014 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+import (
+	"encoding/json"
+	"expvar"
+)
+
+type expvarCollector struct {
+	exports map[string]*Desc
+}
+
+// NewExpvarCollector is the obsolete version of collectors.NewExpvarCollector.
+// See there for documentation.
+//
+// Deprecated: Use collectors.NewExpvarCollector instead.
+func NewExpvarCollector(exports map[string]*Desc) Collector {
+	return &expvarCollector{
+		exports: exports,
+	}
+}
+
+// Describe implements Collector.
+func (e *expvarCollector) Describe(ch chan<- *Desc) {
+	for _, desc := range e.exports {
+		ch <- desc
+	}
+}
+
+// Collect implements Collector.
+func (e *expvarCollector) Collect(ch chan<- Metric) {
+	for name, desc := range e.exports {
+		var m Metric
+		expVar := expvar.Get(name)
+		if expVar == nil {
+			continue
+		}
+		var v interface{}
+		labels := make([]string, len(desc.variableLabels))
+		if err := json.Unmarshal([]byte(expVar.String()), &v); err != nil {
+			ch <- NewInvalidMetric(desc, err)
+			continue
+		}
+		var processValue func(v interface{}, i int)
+		processValue = func(v interface{}, i int) {
+			if i >= len(labels) {
+				copiedLabels := append(make([]string, 0, len(labels)), labels...)
+				switch v := v.(type) {
+				case float64:
+					m = MustNewConstMetric(desc, UntypedValue, v, copiedLabels...)
+				case bool:
+					if v {
+						m = MustNewConstMetric(desc, UntypedValue, 1, copiedLabels...)
+					} else {
+						m = MustNewConstMetric(desc, UntypedValue, 0, copiedLabels...)
+					}
+				default:
+					return
+				}
+				ch <- m
+				return
+			}
+			vm, ok := v.(map[string]interface{})
+			if !ok {
+				return
+			}
+			for lv, val := range vm {
+				labels[i] = lv
+				processValue(val, i+1)
+			}
+		}
+		processValue(v, 0)
+	}
+}

vendor/github.com/prometheus/client_golang/prometheus/fnv.go

@@ -0,0 +1,42 @@
+// Copyright 2018 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+// Inline and byte-free variant of hash/fnv's fnv64a.
+
+const (
+	offset64 = 14695981039346656037
+	prime64  = 1099511628211
+)
+
+// hashNew initializies a new fnv64a hash value.
+func hashNew() uint64 {
+	return offset64
+}
+
+// hashAdd adds a string to a fnv64a hash value, returning the updated hash.
+func hashAdd(h uint64, s string) uint64 {
+	for i := 0; i < len(s); i++ {
+		h ^= uint64(s[i])
+		h *= prime64
+	}
+	return h
+}
+
+// hashAddByte adds a byte to a fnv64a hash value, returning the updated hash.
+func hashAddByte(h uint64, b byte) uint64 {
+	h ^= uint64(b)
+	h *= prime64
+	return h
+}

vendor/github.com/prometheus/client_golang/prometheus/gauge.go

@@ -0,0 +1,289 @@
+// Copyright 2014 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+import (
+	"math"
+	"sync/atomic"
+	"time"
+
+	dto "github.com/prometheus/client_model/go"
+)
+
+// Gauge is a Metric that represents a single numerical value that can
+// arbitrarily go up and down.
+//
+// A Gauge is typically used for measured values like temperatures or current
+// memory usage, but also "counts" that can go up and down, like the number of
+// running goroutines.
+//
+// To create Gauge instances, use NewGauge.
+type Gauge interface {
+	Metric
+	Collector
+
+	// Set sets the Gauge to an arbitrary value.
+	Set(float64)
+	// Inc increments the Gauge by 1. Use Add to increment it by arbitrary
+	// values.
+	Inc()
+	// Dec decrements the Gauge by 1. Use Sub to decrement it by arbitrary
+	// values.
+	Dec()
+	// Add adds the given value to the Gauge. (The value can be negative,
+	// resulting in a decrease of the Gauge.)
+	Add(float64)
+	// Sub subtracts the given value from the Gauge. (The value can be
+	// negative, resulting in an increase of the Gauge.)
+	Sub(float64)
+
+	// SetToCurrentTime sets the Gauge to the current Unix time in seconds.
+	SetToCurrentTime()
+}
+
+// GaugeOpts is an alias for Opts. See there for doc comments.
+type GaugeOpts Opts
+
+// NewGauge creates a new Gauge based on the provided GaugeOpts.
+//
+// The returned implementation is optimized for a fast Set method. If you have a
+// choice for managing the value of a Gauge via Set vs. Inc/Dec/Add/Sub, pick
+// the former. For example, the Inc method of the returned Gauge is slower than
+// the Inc method of a Counter returned by NewCounter. This matches the typical
+// scenarios for Gauges and Counters, where the former tends to be Set-heavy and
+// the latter Inc-heavy.
+func NewGauge(opts GaugeOpts) Gauge {
+	desc := NewDesc(
+		BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
+		opts.Help,
+		nil,
+		opts.ConstLabels,
+	)
+	result := &gauge{desc: desc, labelPairs: desc.constLabelPairs}
+	result.init(result) // Init self-collection.
+	return result
+}
+
+type gauge struct {
+	// valBits contains the bits of the represented float64 value. It has
+	// to go first in the struct to guarantee alignment for atomic
+	// operations.  http://golang.org/pkg/sync/atomic/#pkg-note-BUG
+	valBits uint64
+
+	selfCollector
+
+	desc       *Desc
+	labelPairs []*dto.LabelPair
+}
+
+func (g *gauge) Desc() *Desc {
+	return g.desc
+}
+
+func (g *gauge) Set(val float64) {
+	atomic.StoreUint64(&g.valBits, math.Float64bits(val))
+}
+
+func (g *gauge) SetToCurrentTime() {
+	g.Set(float64(time.Now().UnixNano()) / 1e9)
+}
+
+func (g *gauge) Inc() {
+	g.Add(1)
+}
+
+func (g *gauge) Dec() {
+	g.Add(-1)
+}
+
+func (g *gauge) Add(val float64) {
+	for {
+		oldBits := atomic.LoadUint64(&g.valBits)
+		newBits := math.Float64bits(math.Float64frombits(oldBits) + val)
+		if atomic.CompareAndSwapUint64(&g.valBits, oldBits, newBits) {
+			return
+		}
+	}
+}
+
+func (g *gauge) Sub(val float64) {
+	g.Add(val * -1)
+}
+
+func (g *gauge) Write(out *dto.Metric) error {
+	val := math.Float64frombits(atomic.LoadUint64(&g.valBits))
+	return populateMetric(GaugeValue, val, g.labelPairs, nil, out)
+}
+
+// GaugeVec is a Collector that bundles a set of Gauges that all share the same
+// Desc, but have different values for their variable labels. This is used if
+// you want to count the same thing partitioned by various dimensions
+// (e.g. number of operations queued, partitioned by user and operation
+// type). Create instances with NewGaugeVec.
+type GaugeVec struct {
+	*MetricVec
+}
+
+// NewGaugeVec creates a new GaugeVec based on the provided GaugeOpts and
+// partitioned by the given label names.
+func NewGaugeVec(opts GaugeOpts, labelNames []string) *GaugeVec {
+	desc := NewDesc(
+		BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
+		opts.Help,
+		labelNames,
+		opts.ConstLabels,
+	)
+	return &GaugeVec{
+		MetricVec: NewMetricVec(desc, func(lvs ...string) Metric {
+			if len(lvs) != len(desc.variableLabels) {
+				panic(makeInconsistentCardinalityError(desc.fqName, desc.variableLabels, lvs))
+			}
+			result := &gauge{desc: desc, labelPairs: MakeLabelPairs(desc, lvs)}
+			result.init(result) // Init self-collection.
+			return result
+		}),
+	}
+}
+
+// GetMetricWithLabelValues returns the Gauge for the given slice of label
+// values (same order as the variable labels in Desc). If that combination of
+// label values is accessed for the first time, a new Gauge is created.
+//
+// It is possible to call this method without using the returned Gauge to only
+// create the new Gauge but leave it at its starting value 0. See also the
+// SummaryVec example.
+//
+// Keeping the Gauge for later use is possible (and should be considered if
+// performance is critical), but keep in mind that Reset, DeleteLabelValues and
+// Delete can be used to delete the Gauge from the GaugeVec. In that case, the
+// Gauge will still exist, but it will not be exported anymore, even if a
+// Gauge with the same label values is created later. See also the CounterVec
+// example.
+//
+// An error is returned if the number of label values is not the same as the
+// number of variable labels in Desc (minus any curried labels).
+//
+// Note that for more than one label value, this method is prone to mistakes
+// caused by an incorrect order of arguments. Consider GetMetricWith(Labels) as
+// an alternative to avoid that type of mistake. For higher label numbers, the
+// latter has a much more readable (albeit more verbose) syntax, but it comes
+// with a performance overhead (for creating and processing the Labels map).
+func (v *GaugeVec) GetMetricWithLabelValues(lvs ...string) (Gauge, error) {
+	metric, err := v.MetricVec.GetMetricWithLabelValues(lvs...)
+	if metric != nil {
+		return metric.(Gauge), err
+	}
+	return nil, err
+}
+
+// GetMetricWith returns the Gauge for the given Labels map (the label names
+// must match those of the variable labels in Desc). If that label map is
+// accessed for the first time, a new Gauge is created. Implications of
+// creating a Gauge without using it and keeping the Gauge for later use are
+// the same as for GetMetricWithLabelValues.
+//
+// An error is returned if the number and names of the Labels are inconsistent
+// with those of the variable labels in Desc (minus any curried labels).
+//
+// This method is used for the same purpose as
+// GetMetricWithLabelValues(...string). See there for pros and cons of the two
+// methods.
+func (v *GaugeVec) GetMetricWith(labels Labels) (Gauge, error) {
+	metric, err := v.MetricVec.GetMetricWith(labels)
+	if metric != nil {
+		return metric.(Gauge), err
+	}
+	return nil, err
+}
+
+// WithLabelValues works as GetMetricWithLabelValues, but panics where
+// GetMetricWithLabelValues would have returned an error. Not returning an
+// error allows shortcuts like
+//     myVec.WithLabelValues("404", "GET").Add(42)
+func (v *GaugeVec) WithLabelValues(lvs ...string) Gauge {
+	g, err := v.GetMetricWithLabelValues(lvs...)
+	if err != nil {
+		panic(err)
+	}
+	return g
+}
+
+// With works as GetMetricWith, but panics where GetMetricWithLabels would have
+// returned an error. Not returning an error allows shortcuts like
+//     myVec.With(prometheus.Labels{"code": "404", "method": "GET"}).Add(42)
+func (v *GaugeVec) With(labels Labels) Gauge {
+	g, err := v.GetMetricWith(labels)
+	if err != nil {
+		panic(err)
+	}
+	return g
+}
+
+// CurryWith returns a vector curried with the provided labels, i.e. the
+// returned vector has those labels pre-set for all labeled operations performed
+// on it. The cardinality of the curried vector is reduced accordingly. The
+// order of the remaining labels stays the same (just with the curried labels
+// taken out of the sequence – which is relevant for the
+// (GetMetric)WithLabelValues methods). It is possible to curry a curried
+// vector, but only with labels not yet used for currying before.
+//
+// The metrics contained in the GaugeVec are shared between the curried and
+// uncurried vectors. They are just accessed differently. Curried and uncurried
+// vectors behave identically in terms of collection. Only one must be
+// registered with a given registry (usually the uncurried version). The Reset
+// method deletes all metrics, even if called on a curried vector.
+func (v *GaugeVec) CurryWith(labels Labels) (*GaugeVec, error) {
+	vec, err := v.MetricVec.CurryWith(labels)
+	if vec != nil {
+		return &GaugeVec{vec}, err
+	}
+	return nil, err
+}
+
+// MustCurryWith works as CurryWith but panics where CurryWith would have
+// returned an error.
+func (v *GaugeVec) MustCurryWith(labels Labels) *GaugeVec {
+	vec, err := v.CurryWith(labels)
+	if err != nil {
+		panic(err)
+	}
+	return vec
+}
+
+// GaugeFunc is a Gauge whose value is determined at collect time by calling a
+// provided function.
+//
+// To create GaugeFunc instances, use NewGaugeFunc.
+type GaugeFunc interface {
+	Metric
+	Collector
+}
+
+// NewGaugeFunc creates a new GaugeFunc based on the provided GaugeOpts. The
+// value reported is determined by calling the given function from within the
+// Write method. Take into account that metric collection may happen
+// concurrently. Therefore, it must be safe to call the provided function
+// concurrently.
+//
+// NewGaugeFunc is a good way to create an “info” style metric with a constant
+// value of 1. Example:
+// https://github.com/prometheus/common/blob/8558a5b7db3c84fa38b4766966059a7bd5bfa2ee/version/info.go#L36-L56
+func NewGaugeFunc(opts GaugeOpts, function func() float64) GaugeFunc {
+	return newValueFunc(NewDesc(
+		BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
+		opts.Help,
+		nil,
+		opts.ConstLabels,
+	), GaugeValue, function)
+}

vendor/github.com/prometheus/client_golang/prometheus/go_collector.go

@@ -0,0 +1,277 @@
+// Copyright 2018 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+import (
+	"runtime"
+	"runtime/debug"
+	"time"
+)
+
+func goRuntimeMemStats() memStatsMetrics {
+	return memStatsMetrics{
+		{
+			desc: NewDesc(
+				memstatNamespace("alloc_bytes"),
+				"Number of bytes allocated and still in use.",
+				nil, nil,
+			),
+			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.Alloc) },
+			valType: GaugeValue,
+		}, {
+			desc: NewDesc(
+				memstatNamespace("alloc_bytes_total"),
+				"Total number of bytes allocated, even if freed.",
+				nil, nil,
+			),
+			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.TotalAlloc) },
+			valType: CounterValue,
+		}, {
+			desc: NewDesc(
+				memstatNamespace("sys_bytes"),
+				"Number of bytes obtained from system.",
+				nil, nil,
+			),
+			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.Sys) },
+			valType: GaugeValue,
+		}, {
+			desc: NewDesc(
+				memstatNamespace("lookups_total"),
+				"Total number of pointer lookups.",
+				nil, nil,
+			),
+			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.Lookups) },
+			valType: CounterValue,
+		}, {
+			desc: NewDesc(
+				memstatNamespace("mallocs_total"),
+				"Total number of mallocs.",
+				nil, nil,
+			),
+			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.Mallocs) },
+			valType: CounterValue,
+		}, {
+			desc: NewDesc(
+				memstatNamespace("frees_total"),
+				"Total number of frees.",
+				nil, nil,
+			),
+			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.Frees) },
+			valType: CounterValue,
+		}, {
+			desc: NewDesc(
+				memstatNamespace("heap_alloc_bytes"),
+				"Number of heap bytes allocated and still in use.",
+				nil, nil,
+			),
+			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.HeapAlloc) },
+			valType: GaugeValue,
+		}, {
+			desc: NewDesc(
+				memstatNamespace("heap_sys_bytes"),
+				"Number of heap bytes obtained from system.",
+				nil, nil,
+			),
+			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.HeapSys) },
+			valType: GaugeValue,
+		}, {
+			desc: NewDesc(
+				memstatNamespace("heap_idle_bytes"),
+				"Number of heap bytes waiting to be used.",
+				nil, nil,
+			),
+			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.HeapIdle) },
+			valType: GaugeValue,
+		}, {
+			desc: NewDesc(
+				memstatNamespace("heap_inuse_bytes"),
+				"Number of heap bytes that are in use.",
+				nil, nil,
+			),
+			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.HeapInuse) },
+			valType: GaugeValue,
+		}, {
+			desc: NewDesc(
+				memstatNamespace("heap_released_bytes"),
+				"Number of heap bytes released to OS.",
+				nil, nil,
+			),
+			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.HeapReleased) },
+			valType: GaugeValue,
+		}, {
+			desc: NewDesc(
+				memstatNamespace("heap_objects"),
+				"Number of allocated objects.",
+				nil, nil,
+			),
+			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.HeapObjects) },
+			valType: GaugeValue,
+		}, {
+			desc: NewDesc(
+				memstatNamespace("stack_inuse_bytes"),
+				"Number of bytes in use by the stack allocator.",
+				nil, nil,
+			),
+			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.StackInuse) },
+			valType: GaugeValue,
+		}, {
+			desc: NewDesc(
+				memstatNamespace("stack_sys_bytes"),
+				"Number of bytes obtained from system for stack allocator.",
+				nil, nil,
+			),
+			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.StackSys) },
+			valType: GaugeValue,
+		}, {
+			desc: NewDesc(
+				memstatNamespace("mspan_inuse_bytes"),
+				"Number of bytes in use by mspan structures.",
+				nil, nil,
+			),
+			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.MSpanInuse) },
+			valType: GaugeValue,
+		}, {
+			desc: NewDesc(
+				memstatNamespace("mspan_sys_bytes"),
+				"Number of bytes used for mspan structures obtained from system.",
+				nil, nil,
+			),
+			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.MSpanSys) },
+			valType: GaugeValue,
+		}, {
+			desc: NewDesc(
+				memstatNamespace("mcache_inuse_bytes"),
+				"Number of bytes in use by mcache structures.",
+				nil, nil,
+			),
+			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.MCacheInuse) },
+			valType: GaugeValue,
+		}, {
+			desc: NewDesc(
+				memstatNamespace("mcache_sys_bytes"),
+				"Number of bytes used for mcache structures obtained from system.",
+				nil, nil,
+			),
+			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.MCacheSys) },
+			valType: GaugeValue,
+		}, {
+			desc: NewDesc(
+				memstatNamespace("buck_hash_sys_bytes"),
+				"Number of bytes used by the profiling bucket hash table.",
+				nil, nil,
+			),
+			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.BuckHashSys) },
+			valType: GaugeValue,
+		}, {
+			desc: NewDesc(
+				memstatNamespace("gc_sys_bytes"),
+				"Number of bytes used for garbage collection system metadata.",
+				nil, nil,
+			),
+			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.GCSys) },
+			valType: GaugeValue,
+		}, {
+			desc: NewDesc(
+				memstatNamespace("other_sys_bytes"),
+				"Number of bytes used for other system allocations.",
+				nil, nil,
+			),
+			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.OtherSys) },
+			valType: GaugeValue,
+		}, {
+			desc: NewDesc(
+				memstatNamespace("next_gc_bytes"),
+				"Number of heap bytes when next garbage collection will take place.",
+				nil, nil,
+			),
+			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.NextGC) },
+			valType: GaugeValue,
+		},
+	}
+}
+
+type baseGoCollector struct {
+	goroutinesDesc *Desc
+	threadsDesc    *Desc
+	gcDesc         *Desc
+	gcLastTimeDesc *Desc
+	goInfoDesc     *Desc
+}
+
+func newBaseGoCollector() baseGoCollector {
+	return baseGoCollector{
+		goroutinesDesc: NewDesc(
+			"go_goroutines",
+			"Number of goroutines that currently exist.",
+			nil, nil),
+		threadsDesc: NewDesc(
+			"go_threads",
+			"Number of OS threads created.",
+			nil, nil),
+		gcDesc: NewDesc(
+			"go_gc_duration_seconds",
+			"A summary of the pause duration of garbage collection cycles.",
+			nil, nil),
+		gcLastTimeDesc: NewDesc(
+			memstatNamespace("last_gc_time_seconds"),
+			"Number of seconds since 1970 of last garbage collection.",
+			nil, nil),
+		goInfoDesc: NewDesc(
+			"go_info",
+			"Information about the Go environment.",
+			nil, Labels{"version": runtime.Version()}),
+	}
+}
+
+// Describe returns all descriptions of the collector.
+func (c *baseGoCollector) Describe(ch chan<- *Desc) {
+	ch <- c.goroutinesDesc
+	ch <- c.threadsDesc
+	ch <- c.gcDesc
+	ch <- c.gcLastTimeDesc
+	ch <- c.goInfoDesc
+}
+
+// Collect returns the current state of all metrics of the collector.
+func (c *baseGoCollector) Collect(ch chan<- Metric) {
+	ch <- MustNewConstMetric(c.goroutinesDesc, GaugeValue, float64(runtime.NumGoroutine()))
+	n, _ := runtime.ThreadCreateProfile(nil)
+	ch <- MustNewConstMetric(c.threadsDesc, GaugeValue, float64(n))
+
+	var stats debug.GCStats
+	stats.PauseQuantiles = make([]time.Duration, 5)
+	debug.ReadGCStats(&stats)
+
+	quantiles := make(map[float64]float64)
+	for idx, pq := range stats.PauseQuantiles[1:] {
+		quantiles[float64(idx+1)/float64(len(stats.PauseQuantiles)-1)] = pq.Seconds()
+	}
+	quantiles[0.0] = stats.PauseQuantiles[0].Seconds()
+	ch <- MustNewConstSummary(c.gcDesc, uint64(stats.NumGC), stats.PauseTotal.Seconds(), quantiles)
+	ch <- MustNewConstMetric(c.gcLastTimeDesc, GaugeValue, float64(stats.LastGC.UnixNano())/1e9)
+	ch <- MustNewConstMetric(c.goInfoDesc, GaugeValue, 1)
+}
+
+func memstatNamespace(s string) string {
+	return "go_memstats_" + s
+}
+
+// memStatsMetrics provide description, evaluator, runtime/metrics name, and
+// value type for memstat metrics.
+// TODO(bwplotka): Remove with end Go 1.16 EOL and replace with runtime/metrics.Description
+type memStatsMetrics []struct {
+	desc    *Desc
+	eval    func(*runtime.MemStats) float64
+	valType ValueType
+}

vendor/github.com/prometheus/client_golang/prometheus/go_collector_go116.go

@@ -0,0 +1,122 @@
+// Copyright 2021 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build !go1.17
+// +build !go1.17
+
+package prometheus
+
+import (
+	"runtime"
+	"sync"
+	"time"
+)
+
+type goCollector struct {
+	base baseGoCollector
+
+	// ms... are memstats related.
+	msLast          *runtime.MemStats // Previously collected memstats.
+	msLastTimestamp time.Time
+	msMtx           sync.Mutex // Protects msLast and msLastTimestamp.
+	msMetrics       memStatsMetrics
+	msRead          func(*runtime.MemStats) // For mocking in tests.
+	msMaxWait       time.Duration           // Wait time for fresh memstats.
+	msMaxAge        time.Duration           // Maximum allowed age of old memstats.
+}
+
+// NewGoCollector is the obsolete version of collectors.NewGoCollector.
+// See there for documentation.
+//
+// Deprecated: Use collectors.NewGoCollector instead.
+func NewGoCollector() Collector {
+	msMetrics := goRuntimeMemStats()
+	msMetrics = append(msMetrics, struct {
+		desc    *Desc
+		eval    func(*runtime.MemStats) float64
+		valType ValueType
+	}{
+		// This metric is omitted in Go1.17+, see https://github.com/prometheus/client_golang/issues/842#issuecomment-861812034
+		desc: NewDesc(
+			memstatNamespace("gc_cpu_fraction"),
+			"The fraction of this program's available CPU time used by the GC since the program started.",
+			nil, nil,
+		),
+		eval:    func(ms *runtime.MemStats) float64 { return ms.GCCPUFraction },
+		valType: GaugeValue,
+	})
+	return &goCollector{
+		base:      newBaseGoCollector(),
+		msLast:    &runtime.MemStats{},
+		msRead:    runtime.ReadMemStats,
+		msMaxWait: time.Second,
+		msMaxAge:  5 * time.Minute,
+		msMetrics: msMetrics,
+	}
+}
+
+// Describe returns all descriptions of the collector.
+func (c *goCollector) Describe(ch chan<- *Desc) {
+	c.base.Describe(ch)
+	for _, i := range c.msMetrics {
+		ch <- i.desc
+	}
+}
+
+// Collect returns the current state of all metrics of the collector.
+func (c *goCollector) Collect(ch chan<- Metric) {
+	var (
+		ms   = &runtime.MemStats{}
+		done = make(chan struct{})
+	)
+	// Start reading memstats first as it might take a while.
+	go func() {
+		c.msRead(ms)
+		c.msMtx.Lock()
+		c.msLast = ms
+		c.msLastTimestamp = time.Now()
+		c.msMtx.Unlock()
+		close(done)
+	}()
+
+	// Collect base non-memory metrics.
+	c.base.Collect(ch)
+
+	timer := time.NewTimer(c.msMaxWait)
+	select {
+	case <-done: // Our own ReadMemStats succeeded in time. Use it.
+		timer.Stop() // Important for high collection frequencies to not pile up timers.
+		c.msCollect(ch, ms)
+		return
+	case <-timer.C: // Time out, use last memstats if possible. Continue below.
+	}
+	c.msMtx.Lock()
+	if time.Since(c.msLastTimestamp) < c.msMaxAge {
+		// Last memstats are recent enough. Collect from them under the lock.
+		c.msCollect(ch, c.msLast)
+		c.msMtx.Unlock()
+		return
+	}
+	// If we are here, the last memstats are too old or don't exist. We have
+	// to wait until our own ReadMemStats finally completes. For that to
+	// happen, we have to release the lock.
+	c.msMtx.Unlock()
+	<-done
+	c.msCollect(ch, ms)
+}
+
+func (c *goCollector) msCollect(ch chan<- Metric, ms *runtime.MemStats) {
+	for _, i := range c.msMetrics {
+		ch <- MustNewConstMetric(i.desc, i.valType, i.eval(ms))
+	}
+}

vendor/github.com/prometheus/client_golang/prometheus/go_collector_latest.go

@@ -0,0 +1,521 @@
+// Copyright 2021 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build go1.17
+// +build go1.17
+
+package prometheus
+
+import (
+	"math"
+	"runtime"
+	"runtime/metrics"
+	"strings"
+	"sync"
+
+	//nolint:staticcheck // Ignore SA1019. Need to keep deprecated package for compatibility.
+	"github.com/golang/protobuf/proto"
+	dto "github.com/prometheus/client_model/go"
+
+	"github.com/prometheus/client_golang/prometheus/internal"
+)
+
+const (
+	goGCHeapTinyAllocsObjects               = "/gc/heap/tiny/allocs:objects"
+	goGCHeapAllocsObjects                   = "/gc/heap/allocs:objects"
+	goGCHeapFreesObjects                    = "/gc/heap/frees:objects"
+	goGCHeapAllocsBytes                     = "/gc/heap/allocs:bytes"
+	goGCHeapObjects                         = "/gc/heap/objects:objects"
+	goGCHeapGoalBytes                       = "/gc/heap/goal:bytes"
+	goMemoryClassesTotalBytes               = "/memory/classes/total:bytes"
+	goMemoryClassesHeapObjectsBytes         = "/memory/classes/heap/objects:bytes"
+	goMemoryClassesHeapUnusedBytes          = "/memory/classes/heap/unused:bytes"
+	goMemoryClassesHeapReleasedBytes        = "/memory/classes/heap/released:bytes"
+	goMemoryClassesHeapFreeBytes            = "/memory/classes/heap/free:bytes"
+	goMemoryClassesHeapStacksBytes          = "/memory/classes/heap/stacks:bytes"
+	goMemoryClassesOSStacksBytes            = "/memory/classes/os-stacks:bytes"
+	goMemoryClassesMetadataMSpanInuseBytes  = "/memory/classes/metadata/mspan/inuse:bytes"
+	goMemoryClassesMetadataMSPanFreeBytes   = "/memory/classes/metadata/mspan/free:bytes"
+	goMemoryClassesMetadataMCacheInuseBytes = "/memory/classes/metadata/mcache/inuse:bytes"
+	goMemoryClassesMetadataMCacheFreeBytes  = "/memory/classes/metadata/mcache/free:bytes"
+	goMemoryClassesProfilingBucketsBytes    = "/memory/classes/profiling/buckets:bytes"
+	goMemoryClassesMetadataOtherBytes       = "/memory/classes/metadata/other:bytes"
+	goMemoryClassesOtherBytes               = "/memory/classes/other:bytes"
+)
+
+// runtime/metrics names required for runtimeMemStats like logic.
+var rmForMemStats = []string{goGCHeapTinyAllocsObjects,
+	goGCHeapAllocsObjects,
+	goGCHeapFreesObjects,
+	goGCHeapAllocsBytes,
+	goGCHeapObjects,
+	goGCHeapGoalBytes,
+	goMemoryClassesTotalBytes,
+	goMemoryClassesHeapObjectsBytes,
+	goMemoryClassesHeapUnusedBytes,
+	goMemoryClassesHeapReleasedBytes,
+	goMemoryClassesHeapFreeBytes,
+	goMemoryClassesHeapStacksBytes,
+	goMemoryClassesOSStacksBytes,
+	goMemoryClassesMetadataMSpanInuseBytes,
+	goMemoryClassesMetadataMSPanFreeBytes,
+	goMemoryClassesMetadataMCacheInuseBytes,
+	goMemoryClassesMetadataMCacheFreeBytes,
+	goMemoryClassesProfilingBucketsBytes,
+	goMemoryClassesMetadataOtherBytes,
+	goMemoryClassesOtherBytes,
+}
+
+func bestEffortLookupRM(lookup []string) []metrics.Description {
+	ret := make([]metrics.Description, 0, len(lookup))
+	for _, rm := range metrics.All() {
+		for _, m := range lookup {
+			if m == rm.Name {
+				ret = append(ret, rm)
+			}
+		}
+	}
+	return ret
+}
+
+type goCollector struct {
+	opt  GoCollectorOptions
+	base baseGoCollector
+
+	// mu protects updates to all fields ensuring a consistent
+	// snapshot is always produced by Collect.
+	mu sync.Mutex
+
+	// rm... fields all pertain to the runtime/metrics package.
+	rmSampleBuf []metrics.Sample
+	rmSampleMap map[string]*metrics.Sample
+	rmMetrics   []collectorMetric
+
+	// With Go 1.17, the runtime/metrics package was introduced.
+	// From that point on, metric names produced by the runtime/metrics
+	// package could be generated from runtime/metrics names. However,
+	// these differ from the old names for the same values.
+	//
+	// This field exist to export the same values under the old names
+	// as well.
+	msMetrics memStatsMetrics
+}
+
+const (
+	// Those are not exposed due to need to move Go collector to another package in v2.
+	// See issue https://github.com/prometheus/client_golang/issues/1030.
+	goRuntimeMemStatsCollection uint32 = 1 << iota
+	goRuntimeMetricsCollection
+)
+
+// GoCollectorOptions should not be used be directly by anything, except `collectors` package.
+// Use it via collectors package instead. See issue
+// https://github.com/prometheus/client_golang/issues/1030.
+//
+// Deprecated: Use collectors.WithGoCollections
+type GoCollectorOptions struct {
+	// EnabledCollection sets what type of collections collector should expose on top of base collection.
+	// By default it's goMemStatsCollection | goRuntimeMetricsCollection.
+	EnabledCollections uint32
+}
+
+func (c GoCollectorOptions) isEnabled(flag uint32) bool {
+	return c.EnabledCollections&flag != 0
+}
+
+const defaultGoCollections = goRuntimeMemStatsCollection
+
+// NewGoCollector is the obsolete version of collectors.NewGoCollector.
+// See there for documentation.
+//
+// Deprecated: Use collectors.NewGoCollector instead.
+func NewGoCollector(opts ...func(o *GoCollectorOptions)) Collector {
+	opt := GoCollectorOptions{EnabledCollections: defaultGoCollections}
+	for _, o := range opts {
+		o(&opt)
+	}
+
+	var descriptions []metrics.Description
+	if opt.isEnabled(goRuntimeMetricsCollection) {
+		descriptions = metrics.All()
+	} else if opt.isEnabled(goRuntimeMemStatsCollection) {
+		descriptions = bestEffortLookupRM(rmForMemStats)
+	}
+
+	// Collect all histogram samples so that we can get their buckets.
+	// The API guarantees that the buckets are always fixed for the lifetime
+	// of the process.
+	var histograms []metrics.Sample
+	for _, d := range descriptions {
+		if d.Kind == metrics.KindFloat64Histogram {
+			histograms = append(histograms, metrics.Sample{Name: d.Name})
+		}
+	}
+
+	if len(histograms) > 0 {
+		metrics.Read(histograms)
+	}
+
+	bucketsMap := make(map[string][]float64)
+	for i := range histograms {
+		bucketsMap[histograms[i].Name] = histograms[i].Value.Float64Histogram().Buckets
+	}
+
+	// Generate a Desc and ValueType for each runtime/metrics metric.
+	metricSet := make([]collectorMetric, 0, len(descriptions))
+	sampleBuf := make([]metrics.Sample, 0, len(descriptions))
+	sampleMap := make(map[string]*metrics.Sample, len(descriptions))
+	for i := range descriptions {
+		d := &descriptions[i]
+		namespace, subsystem, name, ok := internal.RuntimeMetricsToProm(d)
+		if !ok {
+			// Just ignore this metric; we can't do anything with it here.
+			// If a user decides to use the latest version of Go, we don't want
+			// to fail here. This condition is tested in TestExpectedRuntimeMetrics.
+			continue
+		}
+
+		// Set up sample buffer for reading, and a map
+		// for quick lookup of sample values.
+		sampleBuf = append(sampleBuf, metrics.Sample{Name: d.Name})
+		sampleMap[d.Name] = &sampleBuf[len(sampleBuf)-1]
+
+		var m collectorMetric
+		if d.Kind == metrics.KindFloat64Histogram {
+			_, hasSum := rmExactSumMap[d.Name]
+			unit := d.Name[strings.IndexRune(d.Name, ':')+1:]
+			m = newBatchHistogram(
+				NewDesc(
+					BuildFQName(namespace, subsystem, name),
+					d.Description,
+					nil,
+					nil,
+				),
+				internal.RuntimeMetricsBucketsForUnit(bucketsMap[d.Name], unit),
+				hasSum,
+			)
+		} else if d.Cumulative {
+			m = NewCounter(CounterOpts{
+				Namespace: namespace,
+				Subsystem: subsystem,
+				Name:      name,
+				Help:      d.Description,
+			})
+		} else {
+			m = NewGauge(GaugeOpts{
+				Namespace: namespace,
+				Subsystem: subsystem,
+				Name:      name,
+				Help:      d.Description,
+			})
+		}
+		metricSet = append(metricSet, m)
+	}
+
+	var msMetrics memStatsMetrics
+	if opt.isEnabled(goRuntimeMemStatsCollection) {
+		msMetrics = goRuntimeMemStats()
+	}
+	return &goCollector{
+		opt:         opt,
+		base:        newBaseGoCollector(),
+		rmSampleBuf: sampleBuf,
+		rmSampleMap: sampleMap,
+		rmMetrics:   metricSet,
+		msMetrics:   msMetrics,
+	}
+}
+
+// Describe returns all descriptions of the collector.
+func (c *goCollector) Describe(ch chan<- *Desc) {
+	c.base.Describe(ch)
+	for _, i := range c.msMetrics {
+		ch <- i.desc
+	}
+	for _, m := range c.rmMetrics {
+		ch <- m.Desc()
+	}
+}
+
+// Collect returns the current state of all metrics of the collector.
+func (c *goCollector) Collect(ch chan<- Metric) {
+	// Collect base non-memory metrics.
+	c.base.Collect(ch)
+
+	// Collect must be thread-safe, so prevent concurrent use of
+	// rmSampleBuf. Just read into rmSampleBuf but write all the data
+	// we get into our Metrics or MemStats.
+	//
+	// This lock also ensures that the Metrics we send out are all from
+	// the same updates, ensuring their mutual consistency insofar as
+	// is guaranteed by the runtime/metrics package.
+	//
+	// N.B. This locking is heavy-handed, but Collect is expected to be called
+	// relatively infrequently. Also the core operation here, metrics.Read,
+	// is fast (O(tens of microseconds)) so contention should certainly be
+	// low, though channel operations and any allocations may add to that.
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	if len(c.rmSampleBuf) > 0 {
+		// Populate runtime/metrics sample buffer.
+		metrics.Read(c.rmSampleBuf)
+	}
+
+	if c.opt.isEnabled(goRuntimeMetricsCollection) {
+		// Collect all our metrics from rmSampleBuf.
+		for i, sample := range c.rmSampleBuf {
+			// N.B. switch on concrete type because it's significantly more efficient
+			// than checking for the Counter and Gauge interface implementations. In
+			// this case, we control all the types here.
+			switch m := c.rmMetrics[i].(type) {
+			case *counter:
+				// Guard against decreases. This should never happen, but a failure
+				// to do so will result in a panic, which is a harsh consequence for
+				// a metrics collection bug.
+				v0, v1 := m.get(), unwrapScalarRMValue(sample.Value)
+				if v1 > v0 {
+					m.Add(unwrapScalarRMValue(sample.Value) - m.get())
+				}
+				m.Collect(ch)
+			case *gauge:
+				m.Set(unwrapScalarRMValue(sample.Value))
+				m.Collect(ch)
+			case *batchHistogram:
+				m.update(sample.Value.Float64Histogram(), c.exactSumFor(sample.Name))
+				m.Collect(ch)
+			default:
+				panic("unexpected metric type")
+			}
+		}
+	}
+
+	// ms is a dummy MemStats that we populate ourselves so that we can
+	// populate the old metrics from it if goMemStatsCollection is enabled.
+	if c.opt.isEnabled(goRuntimeMemStatsCollection) {
+		var ms runtime.MemStats
+		memStatsFromRM(&ms, c.rmSampleMap)
+		for _, i := range c.msMetrics {
+			ch <- MustNewConstMetric(i.desc, i.valType, i.eval(&ms))
+		}
+	}
+}
+
+// unwrapScalarRMValue unwraps a runtime/metrics value that is assumed
+// to be scalar and returns the equivalent float64 value. Panics if the
+// value is not scalar.
+func unwrapScalarRMValue(v metrics.Value) float64 {
+	switch v.Kind() {
+	case metrics.KindUint64:
+		return float64(v.Uint64())
+	case metrics.KindFloat64:
+		return v.Float64()
+	case metrics.KindBad:
+		// Unsupported metric.
+		//
+		// This should never happen because we always populate our metric
+		// set from the runtime/metrics package.
+		panic("unexpected unsupported metric")
+	default:
+		// Unsupported metric kind.
+		//
+		// This should never happen because we check for this during initialization
+		// and flag and filter metrics whose kinds we don't understand.
+		panic("unexpected unsupported metric kind")
+	}
+}
+
+var rmExactSumMap = map[string]string{
+	"/gc/heap/allocs-by-size:bytes": "/gc/heap/allocs:bytes",
+	"/gc/heap/frees-by-size:bytes":  "/gc/heap/frees:bytes",
+}
+
+// exactSumFor takes a runtime/metrics metric name (that is assumed to
+// be of kind KindFloat64Histogram) and returns its exact sum and whether
+// its exact sum exists.
+//
+// The runtime/metrics API for histograms doesn't currently expose exact
+// sums, but some of the other metrics are in fact exact sums of histograms.
+func (c *goCollector) exactSumFor(rmName string) float64 {
+	sumName, ok := rmExactSumMap[rmName]
+	if !ok {
+		return 0
+	}
+	s, ok := c.rmSampleMap[sumName]
+	if !ok {
+		return 0
+	}
+	return unwrapScalarRMValue(s.Value)
+}
+
+func memStatsFromRM(ms *runtime.MemStats, rm map[string]*metrics.Sample) {
+	lookupOrZero := func(name string) uint64 {
+		if s, ok := rm[name]; ok {
+			return s.Value.Uint64()
+		}
+		return 0
+	}
+
+	// Currently, MemStats adds tiny alloc count to both Mallocs AND Frees.
+	// The reason for this is because MemStats couldn't be extended at the time
+	// but there was a desire to have Mallocs at least be a little more representative,
+	// while having Mallocs - Frees still represent a live object count.
+	// Unfortunately, MemStats doesn't actually export a large allocation count,
+	// so it's impossible to pull this number out directly.
+	tinyAllocs := lookupOrZero(goGCHeapTinyAllocsObjects)
+	ms.Mallocs = lookupOrZero(goGCHeapAllocsObjects) + tinyAllocs
+	ms.Frees = lookupOrZero(goGCHeapFreesObjects) + tinyAllocs
+
+	ms.TotalAlloc = lookupOrZero(goGCHeapAllocsBytes)
+	ms.Sys = lookupOrZero(goMemoryClassesTotalBytes)
+	ms.Lookups = 0 // Already always zero.
+	ms.HeapAlloc = lookupOrZero(goMemoryClassesHeapObjectsBytes)
+	ms.Alloc = ms.HeapAlloc
+	ms.HeapInuse = ms.HeapAlloc + lookupOrZero(goMemoryClassesHeapUnusedBytes)
+	ms.HeapReleased = lookupOrZero(goMemoryClassesHeapReleasedBytes)
+	ms.HeapIdle = ms.HeapReleased + lookupOrZero(goMemoryClassesHeapFreeBytes)
+	ms.HeapSys = ms.HeapInuse + ms.HeapIdle
+	ms.HeapObjects = lookupOrZero(goGCHeapObjects)
+	ms.StackInuse = lookupOrZero(goMemoryClassesHeapStacksBytes)
+	ms.StackSys = ms.StackInuse + lookupOrZero(goMemoryClassesOSStacksBytes)
+	ms.MSpanInuse = lookupOrZero(goMemoryClassesMetadataMSpanInuseBytes)
+	ms.MSpanSys = ms.MSpanInuse + lookupOrZero(goMemoryClassesMetadataMSPanFreeBytes)
+	ms.MCacheInuse = lookupOrZero(goMemoryClassesMetadataMCacheInuseBytes)
+	ms.MCacheSys = ms.MCacheInuse + lookupOrZero(goMemoryClassesMetadataMCacheFreeBytes)
+	ms.BuckHashSys = lookupOrZero(goMemoryClassesProfilingBucketsBytes)
+	ms.GCSys = lookupOrZero(goMemoryClassesMetadataOtherBytes)
+	ms.OtherSys = lookupOrZero(goMemoryClassesOtherBytes)
+	ms.NextGC = lookupOrZero(goGCHeapGoalBytes)
+
+	// N.B. GCCPUFraction is intentionally omitted. This metric is not useful,
+	// and often misleading due to the fact that it's an average over the lifetime
+	// of the process.
+	// See https://github.com/prometheus/client_golang/issues/842#issuecomment-861812034
+	// for more details.
+	ms.GCCPUFraction = 0
+}
+
+// batchHistogram is a mutable histogram that is updated
+// in batches.
+type batchHistogram struct {
+	selfCollector
+
+	// Static fields updated only once.
+	desc   *Desc
+	hasSum bool
+
+	// Because this histogram operates in batches, it just uses a
+	// single mutex for everything. updates are always serialized
+	// but Write calls may operate concurrently with updates.
+	// Contention between these two sources should be rare.
+	mu      sync.Mutex
+	buckets []float64 // Inclusive lower bounds, like runtime/metrics.
+	counts  []uint64
+	sum     float64 // Used if hasSum is true.
+}
+
+// newBatchHistogram creates a new batch histogram value with the given
+// Desc, buckets, and whether or not it has an exact sum available.
+//
+// buckets must always be from the runtime/metrics package, following
+// the same conventions.
+func newBatchHistogram(desc *Desc, buckets []float64, hasSum bool) *batchHistogram {
+	// We need to remove -Inf values. runtime/metrics keeps them around.
+	// But -Inf bucket should not be allowed for prometheus histograms.
+	if buckets[0] == math.Inf(-1) {
+		buckets = buckets[1:]
+	}
+	h := &batchHistogram{
+		desc:    desc,
+		buckets: buckets,
+		// Because buckets follows runtime/metrics conventions, there's
+		// 1 more value in the buckets list than there are buckets represented,
+		// because in runtime/metrics, the bucket values represent *boundaries*,
+		// and non-Inf boundaries are inclusive lower bounds for that bucket.
+		counts: make([]uint64, len(buckets)-1),
+		hasSum: hasSum,
+	}
+	h.init(h)
+	return h
+}
+
+// update updates the batchHistogram from a runtime/metrics histogram.
+//
+// sum must be provided if the batchHistogram was created to have an exact sum.
+// h.buckets must be a strict subset of his.Buckets.
+func (h *batchHistogram) update(his *metrics.Float64Histogram, sum float64) {
+	counts, buckets := his.Counts, his.Buckets
+
+	h.mu.Lock()
+	defer h.mu.Unlock()
+
+	// Clear buckets.
+	for i := range h.counts {
+		h.counts[i] = 0
+	}
+	// Copy and reduce buckets.
+	var j int
+	for i, count := range counts {
+		h.counts[j] += count
+		if buckets[i+1] == h.buckets[j+1] {
+			j++
+		}
+	}
+	if h.hasSum {
+		h.sum = sum
+	}
+}
+
+func (h *batchHistogram) Desc() *Desc {
+	return h.desc
+}
+
+func (h *batchHistogram) Write(out *dto.Metric) error {
+	h.mu.Lock()
+	defer h.mu.Unlock()
+
+	sum := float64(0)
+	if h.hasSum {
+		sum = h.sum
+	}
+	dtoBuckets := make([]*dto.Bucket, 0, len(h.counts))
+	totalCount := uint64(0)
+	for i, count := range h.counts {
+		totalCount += count
+		if !h.hasSum {
+			if count != 0 {
+				// N.B. This computed sum is an underestimate.
+				sum += h.buckets[i] * float64(count)
+			}
+		}
+
+		// Skip the +Inf bucket, but only for the bucket list.
+		// It must still count for sum and totalCount.
+		if math.IsInf(h.buckets[i+1], 1) {
+			break
+		}
+		// Float64Histogram's upper bound is exclusive, so make it inclusive
+		// by obtaining the next float64 value down, in order.
+		upperBound := math.Nextafter(h.buckets[i+1], h.buckets[i])
+		dtoBuckets = append(dtoBuckets, &dto.Bucket{
+			CumulativeCount: proto.Uint64(totalCount),
+			UpperBound:      proto.Float64(upperBound),
+		})
+	}
+	out.Histogram = &dto.Histogram{
+		Bucket:      dtoBuckets,
+		SampleCount: proto.Uint64(totalCount),
+		SampleSum:   proto.Float64(sum),
+	}
+	return nil
+}

vendor/github.com/prometheus/client_golang/prometheus/histogram.go

@@ -0,0 +1,670 @@
+// Copyright 2015 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+import (
+	"fmt"
+	"math"
+	"runtime"
+	"sort"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	//nolint:staticcheck // Ignore SA1019. Need to keep deprecated package for compatibility.
+	"github.com/golang/protobuf/proto"
+
+	dto "github.com/prometheus/client_model/go"
+)
+
+// A Histogram counts individual observations from an event or sample stream in
+// configurable buckets. Similar to a summary, it also provides a sum of
+// observations and an observation count.
+//
+// On the Prometheus server, quantiles can be calculated from a Histogram using
+// the histogram_quantile function in the query language.
+//
+// Note that Histograms, in contrast to Summaries, can be aggregated with the
+// Prometheus query language (see the documentation for detailed
+// procedures). However, Histograms require the user to pre-define suitable
+// buckets, and they are in general less accurate. The Observe method of a
+// Histogram has a very low performance overhead in comparison with the Observe
+// method of a Summary.
+//
+// To create Histogram instances, use NewHistogram.
+type Histogram interface {
+	Metric
+	Collector
+
+	// Observe adds a single observation to the histogram. Observations are
+	// usually positive or zero. Negative observations are accepted but
+	// prevent current versions of Prometheus from properly detecting
+	// counter resets in the sum of observations. See
+	// https://prometheus.io/docs/practices/histograms/#count-and-sum-of-observations
+	// for details.
+	Observe(float64)
+}
+
+// bucketLabel is used for the label that defines the upper bound of a
+// bucket of a histogram ("le" -> "less or equal").
+const bucketLabel = "le"
+
+// DefBuckets are the default Histogram buckets. The default buckets are
+// tailored to broadly measure the response time (in seconds) of a network
+// service. Most likely, however, you will be required to define buckets
+// customized to your use case.
+var (
+	DefBuckets = []float64{.005, .01, .025, .05, .1, .25, .5, 1, 2.5, 5, 10}
+
+	errBucketLabelNotAllowed = fmt.Errorf(
+		"%q is not allowed as label name in histograms", bucketLabel,
+	)
+)
+
+// LinearBuckets creates 'count' buckets, each 'width' wide, where the lowest
+// bucket has an upper bound of 'start'. The final +Inf bucket is not counted
+// and not included in the returned slice. The returned slice is meant to be
+// used for the Buckets field of HistogramOpts.
+//
+// The function panics if 'count' is zero or negative.
+func LinearBuckets(start, width float64, count int) []float64 {
+	if count < 1 {
+		panic("LinearBuckets needs a positive count")
+	}
+	buckets := make([]float64, count)
+	for i := range buckets {
+		buckets[i] = start
+		start += width
+	}
+	return buckets
+}
+
+// ExponentialBuckets creates 'count' buckets, where the lowest bucket has an
+// upper bound of 'start' and each following bucket's upper bound is 'factor'
+// times the previous bucket's upper bound. The final +Inf bucket is not counted
+// and not included in the returned slice. The returned slice is meant to be
+// used for the Buckets field of HistogramOpts.
+//
+// The function panics if 'count' is 0 or negative, if 'start' is 0 or negative,
+// or if 'factor' is less than or equal 1.
+func ExponentialBuckets(start, factor float64, count int) []float64 {
+	if count < 1 {
+		panic("ExponentialBuckets needs a positive count")
+	}
+	if start <= 0 {
+		panic("ExponentialBuckets needs a positive start value")
+	}
+	if factor <= 1 {
+		panic("ExponentialBuckets needs a factor greater than 1")
+	}
+	buckets := make([]float64, count)
+	for i := range buckets {
+		buckets[i] = start
+		start *= factor
+	}
+	return buckets
+}
+
+// ExponentialBucketsRange creates 'count' buckets, where the lowest bucket is
+// 'min' and the highest bucket is 'max'. The final +Inf bucket is not counted
+// and not included in the returned slice. The returned slice is meant to be
+// used for the Buckets field of HistogramOpts.
+//
+// The function panics if 'count' is 0 or negative, if 'min' is 0 or negative.
+func ExponentialBucketsRange(min, max float64, count int) []float64 {
+	if count < 1 {
+		panic("ExponentialBucketsRange count needs a positive count")
+	}
+	if min <= 0 {
+		panic("ExponentialBucketsRange min needs to be greater than 0")
+	}
+
+	// Formula for exponential buckets.
+	// max = min*growthFactor^(bucketCount-1)
+
+	// We know max/min and highest bucket. Solve for growthFactor.
+	growthFactor := math.Pow(max/min, 1.0/float64(count-1))
+
+	// Now that we know growthFactor, solve for each bucket.
+	buckets := make([]float64, count)
+	for i := 1; i <= count; i++ {
+		buckets[i-1] = min * math.Pow(growthFactor, float64(i-1))
+	}
+	return buckets
+}
+
+// HistogramOpts bundles the options for creating a Histogram metric. It is
+// mandatory to set Name to a non-empty string. All other fields are optional
+// and can safely be left at their zero value, although it is strongly
+// encouraged to set a Help string.
+type HistogramOpts struct {
+	// Namespace, Subsystem, and Name are components of the fully-qualified
+	// name of the Histogram (created by joining these components with
+	// "_"). Only Name is mandatory, the others merely help structuring the
+	// name. Note that the fully-qualified name of the Histogram must be a
+	// valid Prometheus metric name.
+	Namespace string
+	Subsystem string
+	Name      string
+
+	// Help provides information about this Histogram.
+	//
+	// Metrics with the same fully-qualified name must have the same Help
+	// string.
+	Help string
+
+	// ConstLabels are used to attach fixed labels to this metric. Metrics
+	// with the same fully-qualified name must have the same label names in
+	// their ConstLabels.
+	//
+	// ConstLabels are only used rarely. In particular, do not use them to
+	// attach the same labels to all your metrics. Those use cases are
+	// better covered by target labels set by the scraping Prometheus
+	// server, or by one specific metric (e.g. a build_info or a
+	// machine_role metric). See also
+	// https://prometheus.io/docs/instrumenting/writing_exporters/#target-labels-not-static-scraped-labels
+	ConstLabels Labels
+
+	// Buckets defines the buckets into which observations are counted. Each
+	// element in the slice is the upper inclusive bound of a bucket. The
+	// values must be sorted in strictly increasing order. There is no need
+	// to add a highest bucket with +Inf bound, it will be added
+	// implicitly. The default value is DefBuckets.
+	Buckets []float64
+}
+
+// NewHistogram creates a new Histogram based on the provided HistogramOpts. It
+// panics if the buckets in HistogramOpts are not in strictly increasing order.
+//
+// The returned implementation also implements ExemplarObserver. It is safe to
+// perform the corresponding type assertion. Exemplars are tracked separately
+// for each bucket.
+func NewHistogram(opts HistogramOpts) Histogram {
+	return newHistogram(
+		NewDesc(
+			BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
+			opts.Help,
+			nil,
+			opts.ConstLabels,
+		),
+		opts,
+	)
+}
+
+func newHistogram(desc *Desc, opts HistogramOpts, labelValues ...string) Histogram {
+	if len(desc.variableLabels) != len(labelValues) {
+		panic(makeInconsistentCardinalityError(desc.fqName, desc.variableLabels, labelValues))
+	}
+
+	for _, n := range desc.variableLabels {
+		if n == bucketLabel {
+			panic(errBucketLabelNotAllowed)
+		}
+	}
+	for _, lp := range desc.constLabelPairs {
+		if lp.GetName() == bucketLabel {
+			panic(errBucketLabelNotAllowed)
+		}
+	}
+
+	if len(opts.Buckets) == 0 {
+		opts.Buckets = DefBuckets
+	}
+
+	h := &histogram{
+		desc:        desc,
+		upperBounds: opts.Buckets,
+		labelPairs:  MakeLabelPairs(desc, labelValues),
+		counts:      [2]*histogramCounts{{}, {}},
+		now:         time.Now,
+	}
+	for i, upperBound := range h.upperBounds {
+		if i < len(h.upperBounds)-1 {
+			if upperBound >= h.upperBounds[i+1] {
+				panic(fmt.Errorf(
+					"histogram buckets must be in increasing order: %f >= %f",
+					upperBound, h.upperBounds[i+1],
+				))
+			}
+		} else {
+			if math.IsInf(upperBound, +1) {
+				// The +Inf bucket is implicit. Remove it here.
+				h.upperBounds = h.upperBounds[:i]
+			}
+		}
+	}
+	// Finally we know the final length of h.upperBounds and can make buckets
+	// for both counts as well as exemplars:
+	h.counts[0].buckets = make([]uint64, len(h.upperBounds))
+	h.counts[1].buckets = make([]uint64, len(h.upperBounds))
+	h.exemplars = make([]atomic.Value, len(h.upperBounds)+1)
+
+	h.init(h) // Init self-collection.
+	return h
+}
+
+type histogramCounts struct {
+	// sumBits contains the bits of the float64 representing the sum of all
+	// observations. sumBits and count have to go first in the struct to
+	// guarantee alignment for atomic operations.
+	// http://golang.org/pkg/sync/atomic/#pkg-note-BUG
+	sumBits uint64
+	count   uint64
+	buckets []uint64
+}
+
+type histogram struct {
+	// countAndHotIdx enables lock-free writes with use of atomic updates.
+	// The most significant bit is the hot index [0 or 1] of the count field
+	// below. Observe calls update the hot one. All remaining bits count the
+	// number of Observe calls. Observe starts by incrementing this counter,
+	// and finish by incrementing the count field in the respective
+	// histogramCounts, as a marker for completion.
+	//
+	// Calls of the Write method (which are non-mutating reads from the
+	// perspective of the histogram) swap the hot–cold under the writeMtx
+	// lock. A cooldown is awaited (while locked) by comparing the number of
+	// observations with the initiation count. Once they match, then the
+	// last observation on the now cool one has completed. All cool fields must
+	// be merged into the new hot before releasing writeMtx.
+	//
+	// Fields with atomic access first! See alignment constraint:
+	// http://golang.org/pkg/sync/atomic/#pkg-note-BUG
+	countAndHotIdx uint64
+
+	selfCollector
+	desc     *Desc
+	writeMtx sync.Mutex // Only used in the Write method.
+
+	// Two counts, one is "hot" for lock-free observations, the other is
+	// "cold" for writing out a dto.Metric. It has to be an array of
+	// pointers to guarantee 64bit alignment of the histogramCounts, see
+	// http://golang.org/pkg/sync/atomic/#pkg-note-BUG.
+	counts [2]*histogramCounts
+
+	upperBounds []float64
+	labelPairs  []*dto.LabelPair
+	exemplars   []atomic.Value // One more than buckets (to include +Inf), each a *dto.Exemplar.
+
+	now func() time.Time // To mock out time.Now() for testing.
+}
+
+func (h *histogram) Desc() *Desc {
+	return h.desc
+}
+
+func (h *histogram) Observe(v float64) {
+	h.observe(v, h.findBucket(v))
+}
+
+func (h *histogram) ObserveWithExemplar(v float64, e Labels) {
+	i := h.findBucket(v)
+	h.observe(v, i)
+	h.updateExemplar(v, i, e)
+}
+
+func (h *histogram) Write(out *dto.Metric) error {
+	// For simplicity, we protect this whole method by a mutex. It is not in
+	// the hot path, i.e. Observe is called much more often than Write. The
+	// complication of making Write lock-free isn't worth it, if possible at
+	// all.
+	h.writeMtx.Lock()
+	defer h.writeMtx.Unlock()
+
+	// Adding 1<<63 switches the hot index (from 0 to 1 or from 1 to 0)
+	// without touching the count bits. See the struct comments for a full
+	// description of the algorithm.
+	n := atomic.AddUint64(&h.countAndHotIdx, 1<<63)
+	// count is contained unchanged in the lower 63 bits.
+	count := n & ((1 << 63) - 1)
+	// The most significant bit tells us which counts is hot. The complement
+	// is thus the cold one.
+	hotCounts := h.counts[n>>63]
+	coldCounts := h.counts[(^n)>>63]
+
+	// Await cooldown.
+	for count != atomic.LoadUint64(&coldCounts.count) {
+		runtime.Gosched() // Let observations get work done.
+	}
+
+	his := &dto.Histogram{
+		Bucket:      make([]*dto.Bucket, len(h.upperBounds)),
+		SampleCount: proto.Uint64(count),
+		SampleSum:   proto.Float64(math.Float64frombits(atomic.LoadUint64(&coldCounts.sumBits))),
+	}
+	var cumCount uint64
+	for i, upperBound := range h.upperBounds {
+		cumCount += atomic.LoadUint64(&coldCounts.buckets[i])
+		his.Bucket[i] = &dto.Bucket{
+			CumulativeCount: proto.Uint64(cumCount),
+			UpperBound:      proto.Float64(upperBound),
+		}
+		if e := h.exemplars[i].Load(); e != nil {
+			his.Bucket[i].Exemplar = e.(*dto.Exemplar)
+		}
+	}
+	// If there is an exemplar for the +Inf bucket, we have to add that bucket explicitly.
+	if e := h.exemplars[len(h.upperBounds)].Load(); e != nil {
+		b := &dto.Bucket{
+			CumulativeCount: proto.Uint64(count),
+			UpperBound:      proto.Float64(math.Inf(1)),
+			Exemplar:        e.(*dto.Exemplar),
+		}
+		his.Bucket = append(his.Bucket, b)
+	}
+
+	out.Histogram = his
+	out.Label = h.labelPairs
+
+	// Finally add all the cold counts to the new hot counts and reset the cold counts.
+	atomic.AddUint64(&hotCounts.count, count)
+	atomic.StoreUint64(&coldCounts.count, 0)
+	for {
+		oldBits := atomic.LoadUint64(&hotCounts.sumBits)
+		newBits := math.Float64bits(math.Float64frombits(oldBits) + his.GetSampleSum())
+		if atomic.CompareAndSwapUint64(&hotCounts.sumBits, oldBits, newBits) {
+			atomic.StoreUint64(&coldCounts.sumBits, 0)
+			break
+		}
+	}
+	for i := range h.upperBounds {
+		atomic.AddUint64(&hotCounts.buckets[i], atomic.LoadUint64(&coldCounts.buckets[i]))
+		atomic.StoreUint64(&coldCounts.buckets[i], 0)
+	}
+	return nil
+}
+
+// findBucket returns the index of the bucket for the provided value, or
+// len(h.upperBounds) for the +Inf bucket.
+func (h *histogram) findBucket(v float64) int {
+	// TODO(beorn7): For small numbers of buckets (<30), a linear search is
+	// slightly faster than the binary search. If we really care, we could
+	// switch from one search strategy to the other depending on the number
+	// of buckets.
+	//
+	// Microbenchmarks (BenchmarkHistogramNoLabels):
+	// 11 buckets: 38.3 ns/op linear - binary 48.7 ns/op
+	// 100 buckets: 78.1 ns/op linear - binary 54.9 ns/op
+	// 300 buckets: 154 ns/op linear - binary 61.6 ns/op
+	return sort.SearchFloat64s(h.upperBounds, v)
+}
+
+// observe is the implementation for Observe without the findBucket part.
+func (h *histogram) observe(v float64, bucket int) {
+	// We increment h.countAndHotIdx so that the counter in the lower
+	// 63 bits gets incremented. At the same time, we get the new value
+	// back, which we can use to find the currently-hot counts.
+	n := atomic.AddUint64(&h.countAndHotIdx, 1)
+	hotCounts := h.counts[n>>63]
+
+	if bucket < len(h.upperBounds) {
+		atomic.AddUint64(&hotCounts.buckets[bucket], 1)
+	}
+	for {
+		oldBits := atomic.LoadUint64(&hotCounts.sumBits)
+		newBits := math.Float64bits(math.Float64frombits(oldBits) + v)
+		if atomic.CompareAndSwapUint64(&hotCounts.sumBits, oldBits, newBits) {
+			break
+		}
+	}
+	// Increment count last as we take it as a signal that the observation
+	// is complete.
+	atomic.AddUint64(&hotCounts.count, 1)
+}
+
+// updateExemplar replaces the exemplar for the provided bucket. With empty
+// labels, it's a no-op. It panics if any of the labels is invalid.
+func (h *histogram) updateExemplar(v float64, bucket int, l Labels) {
+	if l == nil {
+		return
+	}
+	e, err := newExemplar(v, h.now(), l)
+	if err != nil {
+		panic(err)
+	}
+	h.exemplars[bucket].Store(e)
+}
+
+// HistogramVec is a Collector that bundles a set of Histograms that all share the
+// same Desc, but have different values for their variable labels. This is used
+// if you want to count the same thing partitioned by various dimensions
+// (e.g. HTTP request latencies, partitioned by status code and method). Create
+// instances with NewHistogramVec.
+type HistogramVec struct {
+	*MetricVec
+}
+
+// NewHistogramVec creates a new HistogramVec based on the provided HistogramOpts and
+// partitioned by the given label names.
+func NewHistogramVec(opts HistogramOpts, labelNames []string) *HistogramVec {
+	desc := NewDesc(
+		BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
+		opts.Help,
+		labelNames,
+		opts.ConstLabels,
+	)
+	return &HistogramVec{
+		MetricVec: NewMetricVec(desc, func(lvs ...string) Metric {
+			return newHistogram(desc, opts, lvs...)
+		}),
+	}
+}
+
+// GetMetricWithLabelValues returns the Histogram for the given slice of label
+// values (same order as the variable labels in Desc). If that combination of
+// label values is accessed for the first time, a new Histogram is created.
+//
+// It is possible to call this method without using the returned Histogram to only
+// create the new Histogram but leave it at its starting value, a Histogram without
+// any observations.
+//
+// Keeping the Histogram for later use is possible (and should be considered if
+// performance is critical), but keep in mind that Reset, DeleteLabelValues and
+// Delete can be used to delete the Histogram from the HistogramVec. In that case, the
+// Histogram will still exist, but it will not be exported anymore, even if a
+// Histogram with the same label values is created later. See also the CounterVec
+// example.
+//
+// An error is returned if the number of label values is not the same as the
+// number of variable labels in Desc (minus any curried labels).
+//
+// Note that for more than one label value, this method is prone to mistakes
+// caused by an incorrect order of arguments. Consider GetMetricWith(Labels) as
+// an alternative to avoid that type of mistake. For higher label numbers, the
+// latter has a much more readable (albeit more verbose) syntax, but it comes
+// with a performance overhead (for creating and processing the Labels map).
+// See also the GaugeVec example.
+func (v *HistogramVec) GetMetricWithLabelValues(lvs ...string) (Observer, error) {
+	metric, err := v.MetricVec.GetMetricWithLabelValues(lvs...)
+	if metric != nil {
+		return metric.(Observer), err
+	}
+	return nil, err
+}
+
+// GetMetricWith returns the Histogram for the given Labels map (the label names
+// must match those of the variable labels in Desc). If that label map is
+// accessed for the first time, a new Histogram is created. Implications of
+// creating a Histogram without using it and keeping the Histogram for later use
+// are the same as for GetMetricWithLabelValues.
+//
+// An error is returned if the number and names of the Labels are inconsistent
+// with those of the variable labels in Desc (minus any curried labels).
+//
+// This method is used for the same purpose as
+// GetMetricWithLabelValues(...string). See there for pros and cons of the two
+// methods.
+func (v *HistogramVec) GetMetricWith(labels Labels) (Observer, error) {
+	metric, err := v.MetricVec.GetMetricWith(labels)
+	if metric != nil {
+		return metric.(Observer), err
+	}
+	return nil, err
+}
+
+// WithLabelValues works as GetMetricWithLabelValues, but panics where
+// GetMetricWithLabelValues would have returned an error. Not returning an
+// error allows shortcuts like
+//     myVec.WithLabelValues("404", "GET").Observe(42.21)
+func (v *HistogramVec) WithLabelValues(lvs ...string) Observer {
+	h, err := v.GetMetricWithLabelValues(lvs...)
+	if err != nil {
+		panic(err)
+	}
+	return h
+}
+
+// With works as GetMetricWith but panics where GetMetricWithLabels would have
+// returned an error. Not returning an error allows shortcuts like
+//     myVec.With(prometheus.Labels{"code": "404", "method": "GET"}).Observe(42.21)
+func (v *HistogramVec) With(labels Labels) Observer {
+	h, err := v.GetMetricWith(labels)
+	if err != nil {
+		panic(err)
+	}
+	return h
+}
+
+// CurryWith returns a vector curried with the provided labels, i.e. the
+// returned vector has those labels pre-set for all labeled operations performed
+// on it. The cardinality of the curried vector is reduced accordingly. The
+// order of the remaining labels stays the same (just with the curried labels
+// taken out of the sequence – which is relevant for the
+// (GetMetric)WithLabelValues methods). It is possible to curry a curried
+// vector, but only with labels not yet used for currying before.
+//
+// The metrics contained in the HistogramVec are shared between the curried and
+// uncurried vectors. They are just accessed differently. Curried and uncurried
+// vectors behave identically in terms of collection. Only one must be
+// registered with a given registry (usually the uncurried version). The Reset
+// method deletes all metrics, even if called on a curried vector.
+func (v *HistogramVec) CurryWith(labels Labels) (ObserverVec, error) {
+	vec, err := v.MetricVec.CurryWith(labels)
+	if vec != nil {
+		return &HistogramVec{vec}, err
+	}
+	return nil, err
+}
+
+// MustCurryWith works as CurryWith but panics where CurryWith would have
+// returned an error.
+func (v *HistogramVec) MustCurryWith(labels Labels) ObserverVec {
+	vec, err := v.CurryWith(labels)
+	if err != nil {
+		panic(err)
+	}
+	return vec
+}
+
+type constHistogram struct {
+	desc       *Desc
+	count      uint64
+	sum        float64
+	buckets    map[float64]uint64
+	labelPairs []*dto.LabelPair
+}
+
+func (h *constHistogram) Desc() *Desc {
+	return h.desc
+}
+
+func (h *constHistogram) Write(out *dto.Metric) error {
+	his := &dto.Histogram{}
+	buckets := make([]*dto.Bucket, 0, len(h.buckets))
+
+	his.SampleCount = proto.Uint64(h.count)
+	his.SampleSum = proto.Float64(h.sum)
+
+	for upperBound, count := range h.buckets {
+		buckets = append(buckets, &dto.Bucket{
+			CumulativeCount: proto.Uint64(count),
+			UpperBound:      proto.Float64(upperBound),
+		})
+	}
+
+	if len(buckets) > 0 {
+		sort.Sort(buckSort(buckets))
+	}
+	his.Bucket = buckets
+
+	out.Histogram = his
+	out.Label = h.labelPairs
+
+	return nil
+}
+
+// NewConstHistogram returns a metric representing a Prometheus histogram with
+// fixed values for the count, sum, and bucket counts. As those parameters
+// cannot be changed, the returned value does not implement the Histogram
+// interface (but only the Metric interface). Users of this package will not
+// have much use for it in regular operations. However, when implementing custom
+// Collectors, it is useful as a throw-away metric that is generated on the fly
+// to send it to Prometheus in the Collect method.
+//
+// buckets is a map of upper bounds to cumulative counts, excluding the +Inf
+// bucket.
+//
+// NewConstHistogram returns an error if the length of labelValues is not
+// consistent with the variable labels in Desc or if Desc is invalid.
+func NewConstHistogram(
+	desc *Desc,
+	count uint64,
+	sum float64,
+	buckets map[float64]uint64,
+	labelValues ...string,
+) (Metric, error) {
+	if desc.err != nil {
+		return nil, desc.err
+	}
+	if err := validateLabelValues(labelValues, len(desc.variableLabels)); err != nil {
+		return nil, err
+	}
+	return &constHistogram{
+		desc:       desc,
+		count:      count,
+		sum:        sum,
+		buckets:    buckets,
+		labelPairs: MakeLabelPairs(desc, labelValues),
+	}, nil
+}
+
+// MustNewConstHistogram is a version of NewConstHistogram that panics where
+// NewConstHistogram would have returned an error.
+func MustNewConstHistogram(
+	desc *Desc,
+	count uint64,
+	sum float64,
+	buckets map[float64]uint64,
+	labelValues ...string,
+) Metric {
+	m, err := NewConstHistogram(desc, count, sum, buckets, labelValues...)
+	if err != nil {
+		panic(err)
+	}
+	return m
+}
+
+type buckSort []*dto.Bucket
+
+func (s buckSort) Len() int {
+	return len(s)
+}
+
+func (s buckSort) Swap(i, j int) {
+	s[i], s[j] = s[j], s[i]
+}
+
+func (s buckSort) Less(i, j int) bool {
+	return s[i].GetUpperBound() < s[j].GetUpperBound()
+}

vendor/github.com/prometheus/client_golang/prometheus/internal/go_runtime_metrics.go

@@ -0,0 +1,142 @@
+// Copyright 2021 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build go1.17
+// +build go1.17
+
+package internal
+
+import (
+	"math"
+	"path"
+	"runtime/metrics"
+	"strings"
+
+	"github.com/prometheus/common/model"
+)
+
+// RuntimeMetricsToProm produces a Prometheus metric name from a runtime/metrics
+// metric description and validates whether the metric is suitable for integration
+// with Prometheus.
+//
+// Returns false if a name could not be produced, or if Prometheus does not understand
+// the runtime/metrics Kind.
+//
+// Note that the main reason a name couldn't be produced is if the runtime/metrics
+// package exports a name with characters outside the valid Prometheus metric name
+// character set. This is theoretically possible, but should never happen in practice.
+// Still, don't rely on it.
+func RuntimeMetricsToProm(d *metrics.Description) (string, string, string, bool) {
+	namespace := "go"
+
+	comp := strings.SplitN(d.Name, ":", 2)
+	key := comp[0]
+	unit := comp[1]
+
+	// The last path element in the key is the name,
+	// the rest is the subsystem.
+	subsystem := path.Dir(key[1:] /* remove leading / */)
+	name := path.Base(key)
+
+	// subsystem is translated by replacing all / and - with _.
+	subsystem = strings.ReplaceAll(subsystem, "/", "_")
+	subsystem = strings.ReplaceAll(subsystem, "-", "_")
+
+	// unit is translated assuming that the unit contains no
+	// non-ASCII characters.
+	unit = strings.ReplaceAll(unit, "-", "_")
+	unit = strings.ReplaceAll(unit, "*", "_")
+	unit = strings.ReplaceAll(unit, "/", "_per_")
+
+	// name has - replaced with _ and is concatenated with the unit and
+	// other data.
+	name = strings.ReplaceAll(name, "-", "_")
+	name = name + "_" + unit
+	if d.Cumulative && d.Kind != metrics.KindFloat64Histogram {
+		name = name + "_total"
+	}
+
+	valid := model.IsValidMetricName(model.LabelValue(namespace + "_" + subsystem + "_" + name))
+	switch d.Kind {
+	case metrics.KindUint64:
+	case metrics.KindFloat64:
+	case metrics.KindFloat64Histogram:
+	default:
+		valid = false
+	}
+	return namespace, subsystem, name, valid
+}
+
+// RuntimeMetricsBucketsForUnit takes a set of buckets obtained for a runtime/metrics histogram
+// type (so, lower-bound inclusive) and a unit from a runtime/metrics name, and produces
+// a reduced set of buckets. This function always removes any -Inf bucket as it's represented
+// as the bottom-most upper-bound inclusive bucket in Prometheus.
+func RuntimeMetricsBucketsForUnit(buckets []float64, unit string) []float64 {
+	switch unit {
+	case "bytes":
+		// Re-bucket as powers of 2.
+		return reBucketExp(buckets, 2)
+	case "seconds":
+		// Re-bucket as powers of 10 and then merge all buckets greater
+		// than 1 second into the +Inf bucket.
+		b := reBucketExp(buckets, 10)
+		for i := range b {
+			if b[i] <= 1 {
+				continue
+			}
+			b[i] = math.Inf(1)
+			b = b[:i+1]
+			break
+		}
+		return b
+	}
+	return buckets
+}
+
+// reBucketExp takes a list of bucket boundaries (lower bound inclusive) and
+// downsamples the buckets to those a multiple of base apart. The end result
+// is a roughly exponential (in many cases, perfectly exponential) bucketing
+// scheme.
+func reBucketExp(buckets []float64, base float64) []float64 {
+	bucket := buckets[0]
+	var newBuckets []float64
+	// We may see a -Inf here, in which case, add it and skip it
+	// since we risk producing NaNs otherwise.
+	//
+	// We need to preserve -Inf values to maintain runtime/metrics
+	// conventions. We'll strip it out later.
+	if bucket == math.Inf(-1) {
+		newBuckets = append(newBuckets, bucket)
+		buckets = buckets[1:]
+		bucket = buckets[0]
+	}
+	// From now on, bucket should always have a non-Inf value because
+	// Infs are only ever at the ends of the bucket lists, so
+	// arithmetic operations on it are non-NaN.
+	for i := 1; i < len(buckets); i++ {
+		if bucket >= 0 && buckets[i] < bucket*base {
+			// The next bucket we want to include is at least bucket*base.
+			continue
+		} else if bucket < 0 && buckets[i] < bucket/base {
+			// In this case the bucket we're targeting is negative, and since
+			// we're ascending through buckets here, we need to divide to get
+			// closer to zero exponentially.
+			continue
+		}
+		// The +Inf bucket will always be the last one, and we'll always
+		// end up including it here because bucket
+		newBuckets = append(newBuckets, bucket)
+		bucket = buckets[i]
+	}
+	return append(newBuckets, bucket)
+}

vendor/github.com/prometheus/client_golang/prometheus/internal/metric.go

@@ -0,0 +1,85 @@
+// Copyright 2018 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package internal
+
+import (
+	"sort"
+
+	dto "github.com/prometheus/client_model/go"
+)
+
+// metricSorter is a sortable slice of *dto.Metric.
+type metricSorter []*dto.Metric
+
+func (s metricSorter) Len() int {
+	return len(s)
+}
+
+func (s metricSorter) Swap(i, j int) {
+	s[i], s[j] = s[j], s[i]
+}
+
+func (s metricSorter) Less(i, j int) bool {
+	if len(s[i].Label) != len(s[j].Label) {
+		// This should not happen. The metrics are
+		// inconsistent. However, we have to deal with the fact, as
+		// people might use custom collectors or metric family injection
+		// to create inconsistent metrics. So let's simply compare the
+		// number of labels in this case. That will still yield
+		// reproducible sorting.
+		return len(s[i].Label) < len(s[j].Label)
+	}
+	for n, lp := range s[i].Label {
+		vi := lp.GetValue()
+		vj := s[j].Label[n].GetValue()
+		if vi != vj {
+			return vi < vj
+		}
+	}
+
+	// We should never arrive here. Multiple metrics with the same
+	// label set in the same scrape will lead to undefined ingestion
+	// behavior. However, as above, we have to provide stable sorting
+	// here, even for inconsistent metrics. So sort equal metrics
+	// by their timestamp, with missing timestamps (implying "now")
+	// coming last.
+	if s[i].TimestampMs == nil {
+		return false
+	}
+	if s[j].TimestampMs == nil {
+		return true
+	}
+	return s[i].GetTimestampMs() < s[j].GetTimestampMs()
+}
+
+// NormalizeMetricFamilies returns a MetricFamily slice with empty
+// MetricFamilies pruned and the remaining MetricFamilies sorted by name within
+// the slice, with the contained Metrics sorted within each MetricFamily.
+func NormalizeMetricFamilies(metricFamiliesByName map[string]*dto.MetricFamily) []*dto.MetricFamily {
+	for _, mf := range metricFamiliesByName {
+		sort.Sort(metricSorter(mf.Metric))
+	}
+	names := make([]string, 0, len(metricFamiliesByName))
+	for name, mf := range metricFamiliesByName {
+		if len(mf.Metric) > 0 {
+			names = append(names, name)
+		}
+	}
+	sort.Strings(names)
+	result := make([]*dto.MetricFamily, 0, len(names))
+	for _, name := range names {
+		result = append(result, metricFamiliesByName[name])
+	}
+	return result
+}

vendor/github.com/prometheus/client_golang/prometheus/labels.go

@@ -0,0 +1,87 @@
+// Copyright 2018 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+	"unicode/utf8"
+
+	"github.com/prometheus/common/model"
+)
+
+// Labels represents a collection of label name -> value mappings. This type is
+// commonly used with the With(Labels) and GetMetricWith(Labels) methods of
+// metric vector Collectors, e.g.:
+//     myVec.With(Labels{"code": "404", "method": "GET"}).Add(42)
+//
+// The other use-case is the specification of constant label pairs in Opts or to
+// create a Desc.
+type Labels map[string]string
+
+// reservedLabelPrefix is a prefix which is not legal in user-supplied
+// label names.
+const reservedLabelPrefix = "__"
+
+var errInconsistentCardinality = errors.New("inconsistent label cardinality")
+
+func makeInconsistentCardinalityError(fqName string, labels, labelValues []string) error {
+	return fmt.Errorf(
+		"%s: %q has %d variable labels named %q but %d values %q were provided",
+		errInconsistentCardinality, fqName,
+		len(labels), labels,
+		len(labelValues), labelValues,
+	)
+}
+
+func validateValuesInLabels(labels Labels, expectedNumberOfValues int) error {
+	if len(labels) != expectedNumberOfValues {
+		return fmt.Errorf(
+			"%s: expected %d label values but got %d in %#v",
+			errInconsistentCardinality, expectedNumberOfValues,
+			len(labels), labels,
+		)
+	}
+
+	for name, val := range labels {
+		if !utf8.ValidString(val) {
+			return fmt.Errorf("label %s: value %q is not valid UTF-8", name, val)
+		}
+	}
+
+	return nil
+}
+
+func validateLabelValues(vals []string, expectedNumberOfValues int) error {
+	if len(vals) != expectedNumberOfValues {
+		return fmt.Errorf(
+			"%s: expected %d label values but got %d in %#v",
+			errInconsistentCardinality, expectedNumberOfValues,
+			len(vals), vals,
+		)
+	}
+
+	for _, val := range vals {
+		if !utf8.ValidString(val) {
+			return fmt.Errorf("label value %q is not valid UTF-8", val)
+		}
+	}
+
+	return nil
+}
+
+func checkLabelName(l string) bool {
+	return model.LabelName(l).IsValid() && !strings.HasPrefix(l, reservedLabelPrefix)
+}

vendor/github.com/prometheus/client_golang/prometheus/metric.go

@@ -0,0 +1,176 @@
+// Copyright 2014 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+import (
+	"strings"
+	"time"
+
+	//nolint:staticcheck // Ignore SA1019. Need to keep deprecated package for compatibility.
+	"github.com/golang/protobuf/proto"
+	"github.com/prometheus/common/model"
+
+	dto "github.com/prometheus/client_model/go"
+)
+
+var separatorByteSlice = []byte{model.SeparatorByte} // For convenient use with xxhash.
+
+// A Metric models a single sample value with its meta data being exported to
+// Prometheus. Implementations of Metric in this package are Gauge, Counter,
+// Histogram, Summary, and Untyped.
+type Metric interface {
+	// Desc returns the descriptor for the Metric. This method idempotently
+	// returns the same descriptor throughout the lifetime of the
+	// Metric. The returned descriptor is immutable by contract. A Metric
+	// unable to describe itself must return an invalid descriptor (created
+	// with NewInvalidDesc).
+	Desc() *Desc
+	// Write encodes the Metric into a "Metric" Protocol Buffer data
+	// transmission object.
+	//
+	// Metric implementations must observe concurrency safety as reads of
+	// this metric may occur at any time, and any blocking occurs at the
+	// expense of total performance of rendering all registered
+	// metrics. Ideally, Metric implementations should support concurrent
+	// readers.
+	//
+	// While populating dto.Metric, it is the responsibility of the
+	// implementation to ensure validity of the Metric protobuf (like valid
+	// UTF-8 strings or syntactically valid metric and label names). It is
+	// recommended to sort labels lexicographically. Callers of Write should
+	// still make sure of sorting if they depend on it.
+	Write(*dto.Metric) error
+	// TODO(beorn7): The original rationale of passing in a pre-allocated
+	// dto.Metric protobuf to save allocations has disappeared. The
+	// signature of this method should be changed to "Write() (*dto.Metric,
+	// error)".
+}
+
+// Opts bundles the options for creating most Metric types. Each metric
+// implementation XXX has its own XXXOpts type, but in most cases, it is just
+// an alias of this type (which might change when the requirement arises.)
+//
+// It is mandatory to set Name to a non-empty string. All other fields are
+// optional and can safely be left at their zero value, although it is strongly
+// encouraged to set a Help string.
+type Opts struct {
+	// Namespace, Subsystem, and Name are components of the fully-qualified
+	// name of the Metric (created by joining these components with
+	// "_"). Only Name is mandatory, the others merely help structuring the
+	// name. Note that the fully-qualified name of the metric must be a
+	// valid Prometheus metric name.
+	Namespace string
+	Subsystem string
+	Name      string
+
+	// Help provides information about this metric.
+	//
+	// Metrics with the same fully-qualified name must have the same Help
+	// string.
+	Help string
+
+	// ConstLabels are used to attach fixed labels to this metric. Metrics
+	// with the same fully-qualified name must have the same label names in
+	// their ConstLabels.
+	//
+	// ConstLabels are only used rarely. In particular, do not use them to
+	// attach the same labels to all your metrics. Those use cases are
+	// better covered by target labels set by the scraping Prometheus
+	// server, or by one specific metric (e.g. a build_info or a
+	// machine_role metric). See also
+	// https://prometheus.io/docs/instrumenting/writing_exporters/#target-labels-not-static-scraped-labels
+	ConstLabels Labels
+}
+
+// BuildFQName joins the given three name components by "_". Empty name
+// components are ignored. If the name parameter itself is empty, an empty
+// string is returned, no matter what. Metric implementations included in this
+// library use this function internally to generate the fully-qualified metric
+// name from the name component in their Opts. Users of the library will only
+// need this function if they implement their own Metric or instantiate a Desc
+// (with NewDesc) directly.
+func BuildFQName(namespace, subsystem, name string) string {
+	if name == "" {
+		return ""
+	}
+	switch {
+	case namespace != "" && subsystem != "":
+		return strings.Join([]string{namespace, subsystem, name}, "_")
+	case namespace != "":
+		return strings.Join([]string{namespace, name}, "_")
+	case subsystem != "":
+		return strings.Join([]string{subsystem, name}, "_")
+	}
+	return name
+}
+
+// labelPairSorter implements sort.Interface. It is used to sort a slice of
+// dto.LabelPair pointers.
+type labelPairSorter []*dto.LabelPair
+
+func (s labelPairSorter) Len() int {
+	return len(s)
+}
+
+func (s labelPairSorter) Swap(i, j int) {
+	s[i], s[j] = s[j], s[i]
+}
+
+func (s labelPairSorter) Less(i, j int) bool {
+	return s[i].GetName() < s[j].GetName()
+}
+
+type invalidMetric struct {
+	desc *Desc
+	err  error
+}
+
+// NewInvalidMetric returns a metric whose Write method always returns the
+// provided error. It is useful if a Collector finds itself unable to collect
+// a metric and wishes to report an error to the registry.
+func NewInvalidMetric(desc *Desc, err error) Metric {
+	return &invalidMetric{desc, err}
+}
+
+func (m *invalidMetric) Desc() *Desc { return m.desc }
+
+func (m *invalidMetric) Write(*dto.Metric) error { return m.err }
+
+type timestampedMetric struct {
+	Metric
+	t time.Time
+}
+
+func (m timestampedMetric) Write(pb *dto.Metric) error {
+	e := m.Metric.Write(pb)
+	pb.TimestampMs = proto.Int64(m.t.Unix()*1000 + int64(m.t.Nanosecond()/1000000))
+	return e
+}
+
+// NewMetricWithTimestamp returns a new Metric wrapping the provided Metric in a
+// way that it has an explicit timestamp set to the provided Time. This is only
+// useful in rare cases as the timestamp of a Prometheus metric should usually
+// be set by the Prometheus server during scraping. Exceptions include mirroring
+// metrics with given timestamps from other metric
+// sources.
+//
+// NewMetricWithTimestamp works best with MustNewConstMetric,
+// MustNewConstHistogram, and MustNewConstSummary, see example.
+//
+// Currently, the exposition formats used by Prometheus are limited to
+// millisecond resolution. Thus, the provided time will be rounded down to the
+// next full millisecond value.
+func NewMetricWithTimestamp(t time.Time, m Metric) Metric {
+	return timestampedMetric{Metric: m, t: t}
+}

vendor/github.com/prometheus/client_golang/prometheus/observer.go

@@ -0,0 +1,64 @@
+// Copyright 2017 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+// Observer is the interface that wraps the Observe method, which is used by
+// Histogram and Summary to add observations.
+type Observer interface {
+	Observe(float64)
+}
+
+// The ObserverFunc type is an adapter to allow the use of ordinary
+// functions as Observers. If f is a function with the appropriate
+// signature, ObserverFunc(f) is an Observer that calls f.
+//
+// This adapter is usually used in connection with the Timer type, and there are
+// two general use cases:
+//
+// The most common one is to use a Gauge as the Observer for a Timer.
+// See the "Gauge" Timer example.
+//
+// The more advanced use case is to create a function that dynamically decides
+// which Observer to use for observing the duration. See the "Complex" Timer
+// example.
+type ObserverFunc func(float64)
+
+// Observe calls f(value). It implements Observer.
+func (f ObserverFunc) Observe(value float64) {
+	f(value)
+}
+
+// ObserverVec is an interface implemented by `HistogramVec` and `SummaryVec`.
+type ObserverVec interface {
+	GetMetricWith(Labels) (Observer, error)
+	GetMetricWithLabelValues(lvs ...string) (Observer, error)
+	With(Labels) Observer
+	WithLabelValues(...string) Observer
+	CurryWith(Labels) (ObserverVec, error)
+	MustCurryWith(Labels) ObserverVec
+
+	Collector
+}
+
+// ExemplarObserver is implemented by Observers that offer the option of
+// observing a value together with an exemplar. Its ObserveWithExemplar method
+// works like the Observe method of an Observer but also replaces the currently
+// saved exemplar (if any) with a new one, created from the provided value, the
+// current time as timestamp, and the provided Labels. Empty Labels will lead to
+// a valid (label-less) exemplar. But if Labels is nil, the current exemplar is
+// left in place. ObserveWithExemplar panics if any of the provided labels are
+// invalid or if the provided labels contain more than 64 runes in total.
+type ExemplarObserver interface {
+	ObserveWithExemplar(value float64, exemplar Labels)
+}

vendor/github.com/prometheus/client_golang/prometheus/process_collector.go

@@ -0,0 +1,166 @@
+// Copyright 2015 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+import (
+	"errors"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"strconv"
+	"strings"
+)
+
+type processCollector struct {
+	collectFn       func(chan<- Metric)
+	pidFn           func() (int, error)
+	reportErrors    bool
+	cpuTotal        *Desc
+	openFDs, maxFDs *Desc
+	vsize, maxVsize *Desc
+	rss             *Desc
+	startTime       *Desc
+}
+
+// ProcessCollectorOpts defines the behavior of a process metrics collector
+// created with NewProcessCollector.
+type ProcessCollectorOpts struct {
+	// PidFn returns the PID of the process the collector collects metrics
+	// for. It is called upon each collection. By default, the PID of the
+	// current process is used, as determined on construction time by
+	// calling os.Getpid().
+	PidFn func() (int, error)
+	// If non-empty, each of the collected metrics is prefixed by the
+	// provided string and an underscore ("_").
+	Namespace string
+	// If true, any error encountered during collection is reported as an
+	// invalid metric (see NewInvalidMetric). Otherwise, errors are ignored
+	// and the collected metrics will be incomplete. (Possibly, no metrics
+	// will be collected at all.) While that's usually not desired, it is
+	// appropriate for the common "mix-in" of process metrics, where process
+	// metrics are nice to have, but failing to collect them should not
+	// disrupt the collection of the remaining metrics.
+	ReportErrors bool
+}
+
+// NewProcessCollector is the obsolete version of collectors.NewProcessCollector.
+// See there for documentation.
+//
+// Deprecated: Use collectors.NewProcessCollector instead.
+func NewProcessCollector(opts ProcessCollectorOpts) Collector {
+	ns := ""
+	if len(opts.Namespace) > 0 {
+		ns = opts.Namespace + "_"
+	}
+
+	c := &processCollector{
+		reportErrors: opts.ReportErrors,
+		cpuTotal: NewDesc(
+			ns+"process_cpu_seconds_total",
+			"Total user and system CPU time spent in seconds.",
+			nil, nil,
+		),
+		openFDs: NewDesc(
+			ns+"process_open_fds",
+			"Number of open file descriptors.",
+			nil, nil,
+		),
+		maxFDs: NewDesc(
+			ns+"process_max_fds",
+			"Maximum number of open file descriptors.",
+			nil, nil,
+		),
+		vsize: NewDesc(
+			ns+"process_virtual_memory_bytes",
+			"Virtual memory size in bytes.",
+			nil, nil,
+		),
+		maxVsize: NewDesc(
+			ns+"process_virtual_memory_max_bytes",
+			"Maximum amount of virtual memory available in bytes.",
+			nil, nil,
+		),
+		rss: NewDesc(
+			ns+"process_resident_memory_bytes",
+			"Resident memory size in bytes.",
+			nil, nil,
+		),
+		startTime: NewDesc(
+			ns+"process_start_time_seconds",
+			"Start time of the process since unix epoch in seconds.",
+			nil, nil,
+		),
+	}
+
+	if opts.PidFn == nil {
+		pid := os.Getpid()
+		c.pidFn = func() (int, error) { return pid, nil }
+	} else {
+		c.pidFn = opts.PidFn
+	}
+
+	// Set up process metric collection if supported by the runtime.
+	if canCollectProcess() {
+		c.collectFn = c.processCollect
+	} else {
+		c.collectFn = func(ch chan<- Metric) {
+			c.reportError(ch, nil, errors.New("process metrics not supported on this platform"))
+		}
+	}
+
+	return c
+}
+
+// Describe returns all descriptions of the collector.
+func (c *processCollector) Describe(ch chan<- *Desc) {
+	ch <- c.cpuTotal
+	ch <- c.openFDs
+	ch <- c.maxFDs
+	ch <- c.vsize
+	ch <- c.maxVsize
+	ch <- c.rss
+	ch <- c.startTime
+}
+
+// Collect returns the current state of all metrics of the collector.
+func (c *processCollector) Collect(ch chan<- Metric) {
+	c.collectFn(ch)
+}
+
+func (c *processCollector) reportError(ch chan<- Metric, desc *Desc, err error) {
+	if !c.reportErrors {
+		return
+	}
+	if desc == nil {
+		desc = NewInvalidDesc(err)
+	}
+	ch <- NewInvalidMetric(desc, err)
+}
+
+// NewPidFileFn returns a function that retrieves a pid from the specified file.
+// It is meant to be used for the PidFn field in ProcessCollectorOpts.
+func NewPidFileFn(pidFilePath string) func() (int, error) {
+	return func() (int, error) {
+		content, err := ioutil.ReadFile(pidFilePath)
+		if err != nil {
+			return 0, fmt.Errorf("can't read pid file %q: %+v", pidFilePath, err)
+		}
+		pid, err := strconv.Atoi(strings.TrimSpace(string(content)))
+		if err != nil {
+			return 0, fmt.Errorf("can't parse pid file %q: %+v", pidFilePath, err)
+		}
+
+		return pid, nil
+	}
+}

vendor/github.com/prometheus/client_golang/prometheus/process_collector_other.go

@@ -0,0 +1,66 @@
+// Copyright 2019 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build !windows
+// +build !windows
+
+package prometheus
+
+import (
+	"github.com/prometheus/procfs"
+)
+
+func canCollectProcess() bool {
+	_, err := procfs.NewDefaultFS()
+	return err == nil
+}
+
+func (c *processCollector) processCollect(ch chan<- Metric) {
+	pid, err := c.pidFn()
+	if err != nil {
+		c.reportError(ch, nil, err)
+		return
+	}
+
+	p, err := procfs.NewProc(pid)
+	if err != nil {
+		c.reportError(ch, nil, err)
+		return
+	}
+
+	if stat, err := p.Stat(); err == nil {
+		ch <- MustNewConstMetric(c.cpuTotal, CounterValue, stat.CPUTime())
+		ch <- MustNewConstMetric(c.vsize, GaugeValue, float64(stat.VirtualMemory()))
+		ch <- MustNewConstMetric(c.rss, GaugeValue, float64(stat.ResidentMemory()))
+		if startTime, err := stat.StartTime(); err == nil {
+			ch <- MustNewConstMetric(c.startTime, GaugeValue, startTime)
+		} else {
+			c.reportError(ch, c.startTime, err)
+		}
+	} else {
+		c.reportError(ch, nil, err)
+	}
+
+	if fds, err := p.FileDescriptorsLen(); err == nil {
+		ch <- MustNewConstMetric(c.openFDs, GaugeValue, float64(fds))
+	} else {
+		c.reportError(ch, c.openFDs, err)
+	}
+
+	if limits, err := p.Limits(); err == nil {
+		ch <- MustNewConstMetric(c.maxFDs, GaugeValue, float64(limits.OpenFiles))
+		ch <- MustNewConstMetric(c.maxVsize, GaugeValue, float64(limits.AddressSpace))
+	} else {
+		c.reportError(ch, nil, err)
+	}
+}

vendor/github.com/prometheus/client_golang/prometheus/process_collector_windows.go

@@ -0,0 +1,116 @@
+// Copyright 2019 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+import (
+	"syscall"
+	"unsafe"
+
+	"golang.org/x/sys/windows"
+)
+
+func canCollectProcess() bool {
+	return true
+}
+
+var (
+	modpsapi    = syscall.NewLazyDLL("psapi.dll")
+	modkernel32 = syscall.NewLazyDLL("kernel32.dll")
+
+	procGetProcessMemoryInfo  = modpsapi.NewProc("GetProcessMemoryInfo")
+	procGetProcessHandleCount = modkernel32.NewProc("GetProcessHandleCount")
+)
+
+type processMemoryCounters struct {
+	// System interface description
+	// https://docs.microsoft.com/en-us/windows/desktop/api/psapi/ns-psapi-process_memory_counters_ex
+
+	// Refer to the Golang internal implementation
+	// https://golang.org/src/internal/syscall/windows/psapi_windows.go
+	_                          uint32
+	PageFaultCount             uint32
+	PeakWorkingSetSize         uintptr
+	WorkingSetSize             uintptr
+	QuotaPeakPagedPoolUsage    uintptr
+	QuotaPagedPoolUsage        uintptr
+	QuotaPeakNonPagedPoolUsage uintptr
+	QuotaNonPagedPoolUsage     uintptr
+	PagefileUsage              uintptr
+	PeakPagefileUsage          uintptr
+	PrivateUsage               uintptr
+}
+
+func getProcessMemoryInfo(handle windows.Handle) (processMemoryCounters, error) {
+	mem := processMemoryCounters{}
+	r1, _, err := procGetProcessMemoryInfo.Call(
+		uintptr(handle),
+		uintptr(unsafe.Pointer(&mem)),
+		uintptr(unsafe.Sizeof(mem)),
+	)
+	if r1 != 1 {
+		return mem, err
+	} else {
+		return mem, nil
+	}
+}
+
+func getProcessHandleCount(handle windows.Handle) (uint32, error) {
+	var count uint32
+	r1, _, err := procGetProcessHandleCount.Call(
+		uintptr(handle),
+		uintptr(unsafe.Pointer(&count)),
+	)
+	if r1 != 1 {
+		return 0, err
+	} else {
+		return count, nil
+	}
+}
+
+func (c *processCollector) processCollect(ch chan<- Metric) {
+	h, err := windows.GetCurrentProcess()
+	if err != nil {
+		c.reportError(ch, nil, err)
+		return
+	}
+
+	var startTime, exitTime, kernelTime, userTime windows.Filetime
+	err = windows.GetProcessTimes(h, &startTime, &exitTime, &kernelTime, &userTime)
+	if err != nil {
+		c.reportError(ch, nil, err)
+		return
+	}
+	ch <- MustNewConstMetric(c.startTime, GaugeValue, float64(startTime.Nanoseconds()/1e9))
+	ch <- MustNewConstMetric(c.cpuTotal, CounterValue, fileTimeToSeconds(kernelTime)+fileTimeToSeconds(userTime))
+
+	mem, err := getProcessMemoryInfo(h)
+	if err != nil {
+		c.reportError(ch, nil, err)
+		return
+	}
+	ch <- MustNewConstMetric(c.vsize, GaugeValue, float64(mem.PrivateUsage))
+	ch <- MustNewConstMetric(c.rss, GaugeValue, float64(mem.WorkingSetSize))
+
+	handles, err := getProcessHandleCount(h)
+	if err != nil {
+		c.reportError(ch, nil, err)
+		return
+	}
+	ch <- MustNewConstMetric(c.openFDs, GaugeValue, float64(handles))
+	ch <- MustNewConstMetric(c.maxFDs, GaugeValue, float64(16*1024*1024)) // Windows has a hard-coded max limit, not per-process.
+}
+
+func fileTimeToSeconds(ft windows.Filetime) float64 {
+	return float64(uint64(ft.HighDateTime)<<32+uint64(ft.LowDateTime)) / 1e7
+}

vendor/github.com/prometheus/client_golang/prometheus/promauto/auto.go

@@ -0,0 +1,376 @@
+// Copyright 2018 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package promauto provides alternative constructors for the fundamental
+// Prometheus metric types and their …Vec and …Func variants. The difference to
+// their counterparts in the prometheus package is that the promauto
+// constructors return Collectors that are already registered with a
+// registry. There are two sets of constructors. The constructors in the first
+// set are top-level functions, while the constructors in the other set are
+// methods of the Factory type. The top-level function return Collectors
+// registered with the global registry (prometheus.DefaultRegisterer), while the
+// methods return Collectors registered with the registry the Factory was
+// constructed with. All constructors panic if the registration fails.
+//
+// The following example is a complete program to create a histogram of normally
+// distributed random numbers from the math/rand package:
+//
+//      package main
+//
+//      import (
+//              "math/rand"
+//              "net/http"
+//
+//              "github.com/prometheus/client_golang/prometheus"
+//              "github.com/prometheus/client_golang/prometheus/promauto"
+//              "github.com/prometheus/client_golang/prometheus/promhttp"
+//      )
+//
+//      var histogram = promauto.NewHistogram(prometheus.HistogramOpts{
+//              Name:    "random_numbers",
+//              Help:    "A histogram of normally distributed random numbers.",
+//              Buckets: prometheus.LinearBuckets(-3, .1, 61),
+//      })
+//
+//      func Random() {
+//              for {
+//                      histogram.Observe(rand.NormFloat64())
+//              }
+//      }
+//
+//      func main() {
+//              go Random()
+//              http.Handle("/metrics", promhttp.Handler())
+//              http.ListenAndServe(":1971", nil)
+//      }
+//
+// Prometheus's version of a minimal hello-world program:
+//
+//      package main
+//
+//      import (
+//      	"fmt"
+//      	"net/http"
+//
+//      	"github.com/prometheus/client_golang/prometheus"
+//      	"github.com/prometheus/client_golang/prometheus/promauto"
+//      	"github.com/prometheus/client_golang/prometheus/promhttp"
+//      )
+//
+//      func main() {
+//      	http.Handle("/", promhttp.InstrumentHandlerCounter(
+//      		promauto.NewCounterVec(
+//      			prometheus.CounterOpts{
+//      				Name: "hello_requests_total",
+//      				Help: "Total number of hello-world requests by HTTP code.",
+//      			},
+//      			[]string{"code"},
+//      		),
+//      		http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+//      			fmt.Fprint(w, "Hello, world!")
+//      		}),
+//      	))
+//      	http.Handle("/metrics", promhttp.Handler())
+//      	http.ListenAndServe(":1971", nil)
+//      }
+//
+// A Factory is created with the With(prometheus.Registerer) function, which
+// enables two usage pattern. With(prometheus.Registerer) can be called once per
+// line:
+//
+//        var (
+//        	reg           = prometheus.NewRegistry()
+//        	randomNumbers = promauto.With(reg).NewHistogram(prometheus.HistogramOpts{
+//        		Name:    "random_numbers",
+//        		Help:    "A histogram of normally distributed random numbers.",
+//        		Buckets: prometheus.LinearBuckets(-3, .1, 61),
+//        	})
+//        	requestCount = promauto.With(reg).NewCounterVec(
+//        		prometheus.CounterOpts{
+//        			Name: "http_requests_total",
+//        			Help: "Total number of HTTP requests by status code and method.",
+//        		},
+//        		[]string{"code", "method"},
+//        	)
+//        )
+//
+// Or it can be used to create a Factory once to be used multiple times:
+//
+//        var (
+//        	reg           = prometheus.NewRegistry()
+//        	factory       = promauto.With(reg)
+//        	randomNumbers = factory.NewHistogram(prometheus.HistogramOpts{
+//        		Name:    "random_numbers",
+//        		Help:    "A histogram of normally distributed random numbers.",
+//        		Buckets: prometheus.LinearBuckets(-3, .1, 61),
+//        	})
+//        	requestCount = factory.NewCounterVec(
+//        		prometheus.CounterOpts{
+//        			Name: "http_requests_total",
+//        			Help: "Total number of HTTP requests by status code and method.",
+//        		},
+//        		[]string{"code", "method"},
+//        	)
+//        )
+//
+// This appears very handy. So why are these constructors locked away in a
+// separate package?
+//
+// The main problem is that registration may fail, e.g. if a metric inconsistent
+// with or equal to the newly to be registered one is already registered.
+// Therefore, the Register method in the prometheus.Registerer interface returns
+// an error, and the same is the case for the top-level prometheus.Register
+// function that registers with the global registry. The prometheus package also
+// provides MustRegister versions for both. They panic if the registration
+// fails, and they clearly call this out by using the Must…  idiom. Panicking is
+// problematic in this case because it doesn't just happen on input provided by
+// the caller that is invalid on its own. Things are a bit more subtle here:
+// Metric creation and registration tend to be spread widely over the
+// codebase. It can easily happen that an incompatible metric is added to an
+// unrelated part of the code, and suddenly code that used to work perfectly
+// fine starts to panic (provided that the registration of the newly added
+// metric happens before the registration of the previously existing
+// metric). This may come as an even bigger surprise with the global registry,
+// where simply importing another package can trigger a panic (if the newly
+// imported package registers metrics in its init function). At least, in the
+// prometheus package, creation of metrics and other collectors is separate from
+// registration. You first create the metric, and then you decide explicitly if
+// you want to register it with a local or the global registry, and if you want
+// to handle the error or risk a panic. With the constructors in the promauto
+// package, registration is automatic, and if it fails, it will always
+// panic. Furthermore, the constructors will often be called in the var section
+// of a file, which means that panicking will happen as a side effect of merely
+// importing a package.
+//
+// A separate package allows conservative users to entirely ignore it. And
+// whoever wants to use it, will do so explicitly, with an opportunity to read
+// this warning.
+//
+// Enjoy promauto responsibly!
+package promauto
+
+import "github.com/prometheus/client_golang/prometheus"
+
+// NewCounter works like the function of the same name in the prometheus package
+// but it automatically registers the Counter with the
+// prometheus.DefaultRegisterer. If the registration fails, NewCounter panics.
+func NewCounter(opts prometheus.CounterOpts) prometheus.Counter {
+	return With(prometheus.DefaultRegisterer).NewCounter(opts)
+}
+
+// NewCounterVec works like the function of the same name in the prometheus
+// package but it automatically registers the CounterVec with the
+// prometheus.DefaultRegisterer. If the registration fails, NewCounterVec
+// panics.
+func NewCounterVec(opts prometheus.CounterOpts, labelNames []string) *prometheus.CounterVec {
+	return With(prometheus.DefaultRegisterer).NewCounterVec(opts, labelNames)
+}
+
+// NewCounterFunc works like the function of the same name in the prometheus
+// package but it automatically registers the CounterFunc with the
+// prometheus.DefaultRegisterer. If the registration fails, NewCounterFunc
+// panics.
+func NewCounterFunc(opts prometheus.CounterOpts, function func() float64) prometheus.CounterFunc {
+	return With(prometheus.DefaultRegisterer).NewCounterFunc(opts, function)
+}
+
+// NewGauge works like the function of the same name in the prometheus package
+// but it automatically registers the Gauge with the
+// prometheus.DefaultRegisterer. If the registration fails, NewGauge panics.
+func NewGauge(opts prometheus.GaugeOpts) prometheus.Gauge {
+	return With(prometheus.DefaultRegisterer).NewGauge(opts)
+}
+
+// NewGaugeVec works like the function of the same name in the prometheus
+// package but it automatically registers the GaugeVec with the
+// prometheus.DefaultRegisterer. If the registration fails, NewGaugeVec panics.
+func NewGaugeVec(opts prometheus.GaugeOpts, labelNames []string) *prometheus.GaugeVec {
+	return With(prometheus.DefaultRegisterer).NewGaugeVec(opts, labelNames)
+}
+
+// NewGaugeFunc works like the function of the same name in the prometheus
+// package but it automatically registers the GaugeFunc with the
+// prometheus.DefaultRegisterer. If the registration fails, NewGaugeFunc panics.
+func NewGaugeFunc(opts prometheus.GaugeOpts, function func() float64) prometheus.GaugeFunc {
+	return With(prometheus.DefaultRegisterer).NewGaugeFunc(opts, function)
+}
+
+// NewSummary works like the function of the same name in the prometheus package
+// but it automatically registers the Summary with the
+// prometheus.DefaultRegisterer. If the registration fails, NewSummary panics.
+func NewSummary(opts prometheus.SummaryOpts) prometheus.Summary {
+	return With(prometheus.DefaultRegisterer).NewSummary(opts)
+}
+
+// NewSummaryVec works like the function of the same name in the prometheus
+// package but it automatically registers the SummaryVec with the
+// prometheus.DefaultRegisterer. If the registration fails, NewSummaryVec
+// panics.
+func NewSummaryVec(opts prometheus.SummaryOpts, labelNames []string) *prometheus.SummaryVec {
+	return With(prometheus.DefaultRegisterer).NewSummaryVec(opts, labelNames)
+}
+
+// NewHistogram works like the function of the same name in the prometheus
+// package but it automatically registers the Histogram with the
+// prometheus.DefaultRegisterer. If the registration fails, NewHistogram panics.
+func NewHistogram(opts prometheus.HistogramOpts) prometheus.Histogram {
+	return With(prometheus.DefaultRegisterer).NewHistogram(opts)
+}
+
+// NewHistogramVec works like the function of the same name in the prometheus
+// package but it automatically registers the HistogramVec with the
+// prometheus.DefaultRegisterer. If the registration fails, NewHistogramVec
+// panics.
+func NewHistogramVec(opts prometheus.HistogramOpts, labelNames []string) *prometheus.HistogramVec {
+	return With(prometheus.DefaultRegisterer).NewHistogramVec(opts, labelNames)
+}
+
+// NewUntypedFunc works like the function of the same name in the prometheus
+// package but it automatically registers the UntypedFunc with the
+// prometheus.DefaultRegisterer. If the registration fails, NewUntypedFunc
+// panics.
+func NewUntypedFunc(opts prometheus.UntypedOpts, function func() float64) prometheus.UntypedFunc {
+	return With(prometheus.DefaultRegisterer).NewUntypedFunc(opts, function)
+}
+
+// Factory provides factory methods to create Collectors that are automatically
+// registered with a Registerer. Create a Factory with the With function,
+// providing a Registerer to auto-register created Collectors with. The zero
+// value of a Factory creates Collectors that are not registered with any
+// Registerer. All methods of the Factory panic if the registration fails.
+type Factory struct {
+	r prometheus.Registerer
+}
+
+// With creates a Factory using the provided Registerer for registration of the
+// created Collectors. If the provided Registerer is nil, the returned Factory
+// creates Collectors that are not registered with any Registerer.
+func With(r prometheus.Registerer) Factory { return Factory{r} }
+
+// NewCounter works like the function of the same name in the prometheus package
+// but it automatically registers the Counter with the Factory's Registerer.
+func (f Factory) NewCounter(opts prometheus.CounterOpts) prometheus.Counter {
+	c := prometheus.NewCounter(opts)
+	if f.r != nil {
+		f.r.MustRegister(c)
+	}
+	return c
+}
+
+// NewCounterVec works like the function of the same name in the prometheus
+// package but it automatically registers the CounterVec with the Factory's
+// Registerer.
+func (f Factory) NewCounterVec(opts prometheus.CounterOpts, labelNames []string) *prometheus.CounterVec {
+	c := prometheus.NewCounterVec(opts, labelNames)
+	if f.r != nil {
+		f.r.MustRegister(c)
+	}
+	return c
+}
+
+// NewCounterFunc works like the function of the same name in the prometheus
+// package but it automatically registers the CounterFunc with the Factory's
+// Registerer.
+func (f Factory) NewCounterFunc(opts prometheus.CounterOpts, function func() float64) prometheus.CounterFunc {
+	c := prometheus.NewCounterFunc(opts, function)
+	if f.r != nil {
+		f.r.MustRegister(c)
+	}
+	return c
+}
+
+// NewGauge works like the function of the same name in the prometheus package
+// but it automatically registers the Gauge with the Factory's Registerer.
+func (f Factory) NewGauge(opts prometheus.GaugeOpts) prometheus.Gauge {
+	g := prometheus.NewGauge(opts)
+	if f.r != nil {
+		f.r.MustRegister(g)
+	}
+	return g
+}
+
+// NewGaugeVec works like the function of the same name in the prometheus
+// package but it automatically registers the GaugeVec with the Factory's
+// Registerer.
+func (f Factory) NewGaugeVec(opts prometheus.GaugeOpts, labelNames []string) *prometheus.GaugeVec {
+	g := prometheus.NewGaugeVec(opts, labelNames)
+	if f.r != nil {
+		f.r.MustRegister(g)
+	}
+	return g
+}
+
+// NewGaugeFunc works like the function of the same name in the prometheus
+// package but it automatically registers the GaugeFunc with the Factory's
+// Registerer.
+func (f Factory) NewGaugeFunc(opts prometheus.GaugeOpts, function func() float64) prometheus.GaugeFunc {
+	g := prometheus.NewGaugeFunc(opts, function)
+	if f.r != nil {
+		f.r.MustRegister(g)
+	}
+	return g
+}
+
+// NewSummary works like the function of the same name in the prometheus package
+// but it automatically registers the Summary with the Factory's Registerer.
+func (f Factory) NewSummary(opts prometheus.SummaryOpts) prometheus.Summary {
+	s := prometheus.NewSummary(opts)
+	if f.r != nil {
+		f.r.MustRegister(s)
+	}
+	return s
+}
+
+// NewSummaryVec works like the function of the same name in the prometheus
+// package but it automatically registers the SummaryVec with the Factory's
+// Registerer.
+func (f Factory) NewSummaryVec(opts prometheus.SummaryOpts, labelNames []string) *prometheus.SummaryVec {
+	s := prometheus.NewSummaryVec(opts, labelNames)
+	if f.r != nil {
+		f.r.MustRegister(s)
+	}
+	return s
+}
+
+// NewHistogram works like the function of the same name in the prometheus
+// package but it automatically registers the Histogram with the Factory's
+// Registerer.
+func (f Factory) NewHistogram(opts prometheus.HistogramOpts) prometheus.Histogram {
+	h := prometheus.NewHistogram(opts)
+	if f.r != nil {
+		f.r.MustRegister(h)
+	}
+	return h
+}
+
+// NewHistogramVec works like the function of the same name in the prometheus
+// package but it automatically registers the HistogramVec with the Factory's
+// Registerer.
+func (f Factory) NewHistogramVec(opts prometheus.HistogramOpts, labelNames []string) *prometheus.HistogramVec {
+	h := prometheus.NewHistogramVec(opts, labelNames)
+	if f.r != nil {
+		f.r.MustRegister(h)
+	}
+	return h
+}
+
+// NewUntypedFunc works like the function of the same name in the prometheus
+// package but it automatically registers the UntypedFunc with the Factory's
+// Registerer.
+func (f Factory) NewUntypedFunc(opts prometheus.UntypedOpts, function func() float64) prometheus.UntypedFunc {
+	u := prometheus.NewUntypedFunc(opts, function)
+	if f.r != nil {
+		f.r.MustRegister(u)
+	}
+	return u
+}

vendor/github.com/prometheus/client_golang/prometheus/promhttp/delegator.go

@@ -0,0 +1,368 @@
+// Copyright 2017 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package promhttp
+
+import (
+	"bufio"
+	"io"
+	"net"
+	"net/http"
+)
+
+const (
+	closeNotifier = 1 << iota
+	flusher
+	hijacker
+	readerFrom
+	pusher
+)
+
+type delegator interface {
+	http.ResponseWriter
+
+	Status() int
+	Written() int64
+}
+
+type responseWriterDelegator struct {
+	http.ResponseWriter
+
+	status             int
+	written            int64
+	wroteHeader        bool
+	observeWriteHeader func(int)
+}
+
+func (r *responseWriterDelegator) Status() int {
+	return r.status
+}
+
+func (r *responseWriterDelegator) Written() int64 {
+	return r.written
+}
+
+func (r *responseWriterDelegator) WriteHeader(code int) {
+	if r.observeWriteHeader != nil && !r.wroteHeader {
+		// Only call observeWriteHeader for the 1st time. It's a bug if
+		// WriteHeader is called more than once, but we want to protect
+		// against it here. Note that we still delegate the WriteHeader
+		// to the original ResponseWriter to not mask the bug from it.
+		r.observeWriteHeader(code)
+	}
+	r.status = code
+	r.wroteHeader = true
+	r.ResponseWriter.WriteHeader(code)
+}
+
+func (r *responseWriterDelegator) Write(b []byte) (int, error) {
+	// If applicable, call WriteHeader here so that observeWriteHeader is
+	// handled appropriately.
+	if !r.wroteHeader {
+		r.WriteHeader(http.StatusOK)
+	}
+	n, err := r.ResponseWriter.Write(b)
+	r.written += int64(n)
+	return n, err
+}
+
+type closeNotifierDelegator struct{ *responseWriterDelegator }
+type flusherDelegator struct{ *responseWriterDelegator }
+type hijackerDelegator struct{ *responseWriterDelegator }
+type readerFromDelegator struct{ *responseWriterDelegator }
+type pusherDelegator struct{ *responseWriterDelegator }
+
+func (d closeNotifierDelegator) CloseNotify() <-chan bool {
+	//nolint:staticcheck // Ignore SA1019. http.CloseNotifier is deprecated but we keep it here to not break existing users.
+	return d.ResponseWriter.(http.CloseNotifier).CloseNotify()
+}
+func (d flusherDelegator) Flush() {
+	// If applicable, call WriteHeader here so that observeWriteHeader is
+	// handled appropriately.
+	if !d.wroteHeader {
+		d.WriteHeader(http.StatusOK)
+	}
+	d.ResponseWriter.(http.Flusher).Flush()
+}
+func (d hijackerDelegator) Hijack() (net.Conn, *bufio.ReadWriter, error) {
+	return d.ResponseWriter.(http.Hijacker).Hijack()
+}
+func (d readerFromDelegator) ReadFrom(re io.Reader) (int64, error) {
+	// If applicable, call WriteHeader here so that observeWriteHeader is
+	// handled appropriately.
+	if !d.wroteHeader {
+		d.WriteHeader(http.StatusOK)
+	}
+	n, err := d.ResponseWriter.(io.ReaderFrom).ReadFrom(re)
+	d.written += n
+	return n, err
+}
+func (d pusherDelegator) Push(target string, opts *http.PushOptions) error {
+	return d.ResponseWriter.(http.Pusher).Push(target, opts)
+}
+
+var pickDelegator = make([]func(*responseWriterDelegator) delegator, 32)
+
+func init() {
+	// TODO(beorn7): Code generation would help here.
+	pickDelegator[0] = func(d *responseWriterDelegator) delegator { // 0
+		return d
+	}
+	pickDelegator[closeNotifier] = func(d *responseWriterDelegator) delegator { // 1
+		return closeNotifierDelegator{d}
+	}
+	pickDelegator[flusher] = func(d *responseWriterDelegator) delegator { // 2
+		return flusherDelegator{d}
+	}
+	pickDelegator[flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 3
+		return struct {
+			*responseWriterDelegator
+			http.Flusher
+			http.CloseNotifier
+		}{d, flusherDelegator{d}, closeNotifierDelegator{d}}
+	}
+	pickDelegator[hijacker] = func(d *responseWriterDelegator) delegator { // 4
+		return hijackerDelegator{d}
+	}
+	pickDelegator[hijacker+closeNotifier] = func(d *responseWriterDelegator) delegator { // 5
+		return struct {
+			*responseWriterDelegator
+			http.Hijacker
+			http.CloseNotifier
+		}{d, hijackerDelegator{d}, closeNotifierDelegator{d}}
+	}
+	pickDelegator[hijacker+flusher] = func(d *responseWriterDelegator) delegator { // 6
+		return struct {
+			*responseWriterDelegator
+			http.Hijacker
+			http.Flusher
+		}{d, hijackerDelegator{d}, flusherDelegator{d}}
+	}
+	pickDelegator[hijacker+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 7
+		return struct {
+			*responseWriterDelegator
+			http.Hijacker
+			http.Flusher
+			http.CloseNotifier
+		}{d, hijackerDelegator{d}, flusherDelegator{d}, closeNotifierDelegator{d}}
+	}
+	pickDelegator[readerFrom] = func(d *responseWriterDelegator) delegator { // 8
+		return readerFromDelegator{d}
+	}
+	pickDelegator[readerFrom+closeNotifier] = func(d *responseWriterDelegator) delegator { // 9
+		return struct {
+			*responseWriterDelegator
+			io.ReaderFrom
+			http.CloseNotifier
+		}{d, readerFromDelegator{d}, closeNotifierDelegator{d}}
+	}
+	pickDelegator[readerFrom+flusher] = func(d *responseWriterDelegator) delegator { // 10
+		return struct {
+			*responseWriterDelegator
+			io.ReaderFrom
+			http.Flusher
+		}{d, readerFromDelegator{d}, flusherDelegator{d}}
+	}
+	pickDelegator[readerFrom+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 11
+		return struct {
+			*responseWriterDelegator
+			io.ReaderFrom
+			http.Flusher
+			http.CloseNotifier
+		}{d, readerFromDelegator{d}, flusherDelegator{d}, closeNotifierDelegator{d}}
+	}
+	pickDelegator[readerFrom+hijacker] = func(d *responseWriterDelegator) delegator { // 12
+		return struct {
+			*responseWriterDelegator
+			io.ReaderFrom
+			http.Hijacker
+		}{d, readerFromDelegator{d}, hijackerDelegator{d}}
+	}
+	pickDelegator[readerFrom+hijacker+closeNotifier] = func(d *responseWriterDelegator) delegator { // 13
+		return struct {
+			*responseWriterDelegator
+			io.ReaderFrom
+			http.Hijacker
+			http.CloseNotifier
+		}{d, readerFromDelegator{d}, hijackerDelegator{d}, closeNotifierDelegator{d}}
+	}
+	pickDelegator[readerFrom+hijacker+flusher] = func(d *responseWriterDelegator) delegator { // 14
+		return struct {
+			*responseWriterDelegator
+			io.ReaderFrom
+			http.Hijacker
+			http.Flusher
+		}{d, readerFromDelegator{d}, hijackerDelegator{d}, flusherDelegator{d}}
+	}
+	pickDelegator[readerFrom+hijacker+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 15
+		return struct {
+			*responseWriterDelegator
+			io.ReaderFrom
+			http.Hijacker
+			http.Flusher
+			http.CloseNotifier
+		}{d, readerFromDelegator{d}, hijackerDelegator{d}, flusherDelegator{d}, closeNotifierDelegator{d}}
+	}
+	pickDelegator[pusher] = func(d *responseWriterDelegator) delegator { // 16
+		return pusherDelegator{d}
+	}
+	pickDelegator[pusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 17
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			http.CloseNotifier
+		}{d, pusherDelegator{d}, closeNotifierDelegator{d}}
+	}
+	pickDelegator[pusher+flusher] = func(d *responseWriterDelegator) delegator { // 18
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			http.Flusher
+		}{d, pusherDelegator{d}, flusherDelegator{d}}
+	}
+	pickDelegator[pusher+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 19
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			http.Flusher
+			http.CloseNotifier
+		}{d, pusherDelegator{d}, flusherDelegator{d}, closeNotifierDelegator{d}}
+	}
+	pickDelegator[pusher+hijacker] = func(d *responseWriterDelegator) delegator { // 20
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			http.Hijacker
+		}{d, pusherDelegator{d}, hijackerDelegator{d}}
+	}
+	pickDelegator[pusher+hijacker+closeNotifier] = func(d *responseWriterDelegator) delegator { // 21
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			http.Hijacker
+			http.CloseNotifier
+		}{d, pusherDelegator{d}, hijackerDelegator{d}, closeNotifierDelegator{d}}
+	}
+	pickDelegator[pusher+hijacker+flusher] = func(d *responseWriterDelegator) delegator { // 22
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			http.Hijacker
+			http.Flusher
+		}{d, pusherDelegator{d}, hijackerDelegator{d}, flusherDelegator{d}}
+	}
+	pickDelegator[pusher+hijacker+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { //23
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			http.Hijacker
+			http.Flusher
+			http.CloseNotifier
+		}{d, pusherDelegator{d}, hijackerDelegator{d}, flusherDelegator{d}, closeNotifierDelegator{d}}
+	}
+	pickDelegator[pusher+readerFrom] = func(d *responseWriterDelegator) delegator { // 24
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			io.ReaderFrom
+		}{d, pusherDelegator{d}, readerFromDelegator{d}}
+	}
+	pickDelegator[pusher+readerFrom+closeNotifier] = func(d *responseWriterDelegator) delegator { // 25
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			io.ReaderFrom
+			http.CloseNotifier
+		}{d, pusherDelegator{d}, readerFromDelegator{d}, closeNotifierDelegator{d}}
+	}
+	pickDelegator[pusher+readerFrom+flusher] = func(d *responseWriterDelegator) delegator { // 26
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			io.ReaderFrom
+			http.Flusher
+		}{d, pusherDelegator{d}, readerFromDelegator{d}, flusherDelegator{d}}
+	}
+	pickDelegator[pusher+readerFrom+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 27
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			io.ReaderFrom
+			http.Flusher
+			http.CloseNotifier
+		}{d, pusherDelegator{d}, readerFromDelegator{d}, flusherDelegator{d}, closeNotifierDelegator{d}}
+	}
+	pickDelegator[pusher+readerFrom+hijacker] = func(d *responseWriterDelegator) delegator { // 28
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			io.ReaderFrom
+			http.Hijacker
+		}{d, pusherDelegator{d}, readerFromDelegator{d}, hijackerDelegator{d}}
+	}
+	pickDelegator[pusher+readerFrom+hijacker+closeNotifier] = func(d *responseWriterDelegator) delegator { // 29
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			io.ReaderFrom
+			http.Hijacker
+			http.CloseNotifier
+		}{d, pusherDelegator{d}, readerFromDelegator{d}, hijackerDelegator{d}, closeNotifierDelegator{d}}
+	}
+	pickDelegator[pusher+readerFrom+hijacker+flusher] = func(d *responseWriterDelegator) delegator { // 30
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			io.ReaderFrom
+			http.Hijacker
+			http.Flusher
+		}{d, pusherDelegator{d}, readerFromDelegator{d}, hijackerDelegator{d}, flusherDelegator{d}}
+	}
+	pickDelegator[pusher+readerFrom+hijacker+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 31
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			io.ReaderFrom
+			http.Hijacker
+			http.Flusher
+			http.CloseNotifier
+		}{d, pusherDelegator{d}, readerFromDelegator{d}, hijackerDelegator{d}, flusherDelegator{d}, closeNotifierDelegator{d}}
+	}
+}
+
+func newDelegator(w http.ResponseWriter, observeWriteHeaderFunc func(int)) delegator {
+	d := &responseWriterDelegator{
+		ResponseWriter:     w,
+		observeWriteHeader: observeWriteHeaderFunc,
+	}
+
+	id := 0
+	//nolint:staticcheck // Ignore SA1019. http.CloseNotifier is deprecated but we keep it here to not break existing users.
+	if _, ok := w.(http.CloseNotifier); ok {
+		id += closeNotifier
+	}
+	if _, ok := w.(http.Flusher); ok {
+		id += flusher
+	}
+	if _, ok := w.(http.Hijacker); ok {
+		id += hijacker
+	}
+	if _, ok := w.(io.ReaderFrom); ok {
+		id += readerFrom
+	}
+	if _, ok := w.(http.Pusher); ok {
+		id += pusher
+	}
+
+	return pickDelegator[id](d)
+}

vendor/github.com/prometheus/client_golang/prometheus/promhttp/http.go

@@ -0,0 +1,383 @@
+// Copyright 2016 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package promhttp provides tooling around HTTP servers and clients.
+//
+// First, the package allows the creation of http.Handler instances to expose
+// Prometheus metrics via HTTP. promhttp.Handler acts on the
+// prometheus.DefaultGatherer. With HandlerFor, you can create a handler for a
+// custom registry or anything that implements the Gatherer interface. It also
+// allows the creation of handlers that act differently on errors or allow to
+// log errors.
+//
+// Second, the package provides tooling to instrument instances of http.Handler
+// via middleware. Middleware wrappers follow the naming scheme
+// InstrumentHandlerX, where X describes the intended use of the middleware.
+// See each function's doc comment for specific details.
+//
+// Finally, the package allows for an http.RoundTripper to be instrumented via
+// middleware. Middleware wrappers follow the naming scheme
+// InstrumentRoundTripperX, where X describes the intended use of the
+// middleware. See each function's doc comment for specific details.
+package promhttp
+
+import (
+	"compress/gzip"
+	"fmt"
+	"io"
+	"net/http"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/prometheus/common/expfmt"
+
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+const (
+	contentTypeHeader     = "Content-Type"
+	contentEncodingHeader = "Content-Encoding"
+	acceptEncodingHeader  = "Accept-Encoding"
+)
+
+var gzipPool = sync.Pool{
+	New: func() interface{} {
+		return gzip.NewWriter(nil)
+	},
+}
+
+// Handler returns an http.Handler for the prometheus.DefaultGatherer, using
+// default HandlerOpts, i.e. it reports the first error as an HTTP error, it has
+// no error logging, and it applies compression if requested by the client.
+//
+// The returned http.Handler is already instrumented using the
+// InstrumentMetricHandler function and the prometheus.DefaultRegisterer. If you
+// create multiple http.Handlers by separate calls of the Handler function, the
+// metrics used for instrumentation will be shared between them, providing
+// global scrape counts.
+//
+// This function is meant to cover the bulk of basic use cases. If you are doing
+// anything that requires more customization (including using a non-default
+// Gatherer, different instrumentation, and non-default HandlerOpts), use the
+// HandlerFor function. See there for details.
+func Handler() http.Handler {
+	return InstrumentMetricHandler(
+		prometheus.DefaultRegisterer, HandlerFor(prometheus.DefaultGatherer, HandlerOpts{}),
+	)
+}
+
+// HandlerFor returns an uninstrumented http.Handler for the provided
+// Gatherer. The behavior of the Handler is defined by the provided
+// HandlerOpts. Thus, HandlerFor is useful to create http.Handlers for custom
+// Gatherers, with non-default HandlerOpts, and/or with custom (or no)
+// instrumentation. Use the InstrumentMetricHandler function to apply the same
+// kind of instrumentation as it is used by the Handler function.
+func HandlerFor(reg prometheus.Gatherer, opts HandlerOpts) http.Handler {
+	var (
+		inFlightSem chan struct{}
+		errCnt      = prometheus.NewCounterVec(
+			prometheus.CounterOpts{
+				Name: "promhttp_metric_handler_errors_total",
+				Help: "Total number of internal errors encountered by the promhttp metric handler.",
+			},
+			[]string{"cause"},
+		)
+	)
+
+	if opts.MaxRequestsInFlight > 0 {
+		inFlightSem = make(chan struct{}, opts.MaxRequestsInFlight)
+	}
+	if opts.Registry != nil {
+		// Initialize all possibilities that can occur below.
+		errCnt.WithLabelValues("gathering")
+		errCnt.WithLabelValues("encoding")
+		if err := opts.Registry.Register(errCnt); err != nil {
+			if are, ok := err.(prometheus.AlreadyRegisteredError); ok {
+				errCnt = are.ExistingCollector.(*prometheus.CounterVec)
+			} else {
+				panic(err)
+			}
+		}
+	}
+
+	h := http.HandlerFunc(func(rsp http.ResponseWriter, req *http.Request) {
+		if inFlightSem != nil {
+			select {
+			case inFlightSem <- struct{}{}: // All good, carry on.
+				defer func() { <-inFlightSem }()
+			default:
+				http.Error(rsp, fmt.Sprintf(
+					"Limit of concurrent requests reached (%d), try again later.", opts.MaxRequestsInFlight,
+				), http.StatusServiceUnavailable)
+				return
+			}
+		}
+		mfs, err := reg.Gather()
+		if err != nil {
+			if opts.ErrorLog != nil {
+				opts.ErrorLog.Println("error gathering metrics:", err)
+			}
+			errCnt.WithLabelValues("gathering").Inc()
+			switch opts.ErrorHandling {
+			case PanicOnError:
+				panic(err)
+			case ContinueOnError:
+				if len(mfs) == 0 {
+					// Still report the error if no metrics have been gathered.
+					httpError(rsp, err)
+					return
+				}
+			case HTTPErrorOnError:
+				httpError(rsp, err)
+				return
+			}
+		}
+
+		var contentType expfmt.Format
+		if opts.EnableOpenMetrics {
+			contentType = expfmt.NegotiateIncludingOpenMetrics(req.Header)
+		} else {
+			contentType = expfmt.Negotiate(req.Header)
+		}
+		header := rsp.Header()
+		header.Set(contentTypeHeader, string(contentType))
+
+		w := io.Writer(rsp)
+		if !opts.DisableCompression && gzipAccepted(req.Header) {
+			header.Set(contentEncodingHeader, "gzip")
+			gz := gzipPool.Get().(*gzip.Writer)
+			defer gzipPool.Put(gz)
+
+			gz.Reset(w)
+			defer gz.Close()
+
+			w = gz
+		}
+
+		enc := expfmt.NewEncoder(w, contentType)
+
+		// handleError handles the error according to opts.ErrorHandling
+		// and returns true if we have to abort after the handling.
+		handleError := func(err error) bool {
+			if err == nil {
+				return false
+			}
+			if opts.ErrorLog != nil {
+				opts.ErrorLog.Println("error encoding and sending metric family:", err)
+			}
+			errCnt.WithLabelValues("encoding").Inc()
+			switch opts.ErrorHandling {
+			case PanicOnError:
+				panic(err)
+			case HTTPErrorOnError:
+				// We cannot really send an HTTP error at this
+				// point because we most likely have written
+				// something to rsp already. But at least we can
+				// stop sending.
+				return true
+			}
+			// Do nothing in all other cases, including ContinueOnError.
+			return false
+		}
+
+		for _, mf := range mfs {
+			if handleError(enc.Encode(mf)) {
+				return
+			}
+		}
+		if closer, ok := enc.(expfmt.Closer); ok {
+			// This in particular takes care of the final "# EOF\n" line for OpenMetrics.
+			if handleError(closer.Close()) {
+				return
+			}
+		}
+	})
+
+	if opts.Timeout <= 0 {
+		return h
+	}
+	return http.TimeoutHandler(h, opts.Timeout, fmt.Sprintf(
+		"Exceeded configured timeout of %v.\n",
+		opts.Timeout,
+	))
+}
+
+// InstrumentMetricHandler is usually used with an http.Handler returned by the
+// HandlerFor function. It instruments the provided http.Handler with two
+// metrics: A counter vector "promhttp_metric_handler_requests_total" to count
+// scrapes partitioned by HTTP status code, and a gauge
+// "promhttp_metric_handler_requests_in_flight" to track the number of
+// simultaneous scrapes. This function idempotently registers collectors for
+// both metrics with the provided Registerer. It panics if the registration
+// fails. The provided metrics are useful to see how many scrapes hit the
+// monitored target (which could be from different Prometheus servers or other
+// scrapers), and how often they overlap (which would result in more than one
+// scrape in flight at the same time). Note that the scrapes-in-flight gauge
+// will contain the scrape by which it is exposed, while the scrape counter will
+// only get incremented after the scrape is complete (as only then the status
+// code is known). For tracking scrape durations, use the
+// "scrape_duration_seconds" gauge created by the Prometheus server upon each
+// scrape.
+func InstrumentMetricHandler(reg prometheus.Registerer, handler http.Handler) http.Handler {
+	cnt := prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Name: "promhttp_metric_handler_requests_total",
+			Help: "Total number of scrapes by HTTP status code.",
+		},
+		[]string{"code"},
+	)
+	// Initialize the most likely HTTP status codes.
+	cnt.WithLabelValues("200")
+	cnt.WithLabelValues("500")
+	cnt.WithLabelValues("503")
+	if err := reg.Register(cnt); err != nil {
+		if are, ok := err.(prometheus.AlreadyRegisteredError); ok {
+			cnt = are.ExistingCollector.(*prometheus.CounterVec)
+		} else {
+			panic(err)
+		}
+	}
+
+	gge := prometheus.NewGauge(prometheus.GaugeOpts{
+		Name: "promhttp_metric_handler_requests_in_flight",
+		Help: "Current number of scrapes being served.",
+	})
+	if err := reg.Register(gge); err != nil {
+		if are, ok := err.(prometheus.AlreadyRegisteredError); ok {
+			gge = are.ExistingCollector.(prometheus.Gauge)
+		} else {
+			panic(err)
+		}
+	}
+
+	return InstrumentHandlerCounter(cnt, InstrumentHandlerInFlight(gge, handler))
+}
+
+// HandlerErrorHandling defines how a Handler serving metrics will handle
+// errors.
+type HandlerErrorHandling int
+
+// These constants cause handlers serving metrics to behave as described if
+// errors are encountered.
+const (
+	// Serve an HTTP status code 500 upon the first error
+	// encountered. Report the error message in the body. Note that HTTP
+	// errors cannot be served anymore once the beginning of a regular
+	// payload has been sent. Thus, in the (unlikely) case that encoding the
+	// payload into the negotiated wire format fails, serving the response
+	// will simply be aborted. Set an ErrorLog in HandlerOpts to detect
+	// those errors.
+	HTTPErrorOnError HandlerErrorHandling = iota
+	// Ignore errors and try to serve as many metrics as possible.  However,
+	// if no metrics can be served, serve an HTTP status code 500 and the
+	// last error message in the body. Only use this in deliberate "best
+	// effort" metrics collection scenarios. In this case, it is highly
+	// recommended to provide other means of detecting errors: By setting an
+	// ErrorLog in HandlerOpts, the errors are logged. By providing a
+	// Registry in HandlerOpts, the exposed metrics include an error counter
+	// "promhttp_metric_handler_errors_total", which can be used for
+	// alerts.
+	ContinueOnError
+	// Panic upon the first error encountered (useful for "crash only" apps).
+	PanicOnError
+)
+
+// Logger is the minimal interface HandlerOpts needs for logging. Note that
+// log.Logger from the standard library implements this interface, and it is
+// easy to implement by custom loggers, if they don't do so already anyway.
+type Logger interface {
+	Println(v ...interface{})
+}
+
+// HandlerOpts specifies options how to serve metrics via an http.Handler. The
+// zero value of HandlerOpts is a reasonable default.
+type HandlerOpts struct {
+	// ErrorLog specifies an optional Logger for errors collecting and
+	// serving metrics. If nil, errors are not logged at all. Note that the
+	// type of a reported error is often prometheus.MultiError, which
+	// formats into a multi-line error string. If you want to avoid the
+	// latter, create a Logger implementation that detects a
+	// prometheus.MultiError and formats the contained errors into one line.
+	ErrorLog Logger
+	// ErrorHandling defines how errors are handled. Note that errors are
+	// logged regardless of the configured ErrorHandling provided ErrorLog
+	// is not nil.
+	ErrorHandling HandlerErrorHandling
+	// If Registry is not nil, it is used to register a metric
+	// "promhttp_metric_handler_errors_total", partitioned by "cause". A
+	// failed registration causes a panic. Note that this error counter is
+	// different from the instrumentation you get from the various
+	// InstrumentHandler... helpers. It counts errors that don't necessarily
+	// result in a non-2xx HTTP status code. There are two typical cases:
+	// (1) Encoding errors that only happen after streaming of the HTTP body
+	// has already started (and the status code 200 has been sent). This
+	// should only happen with custom collectors. (2) Collection errors with
+	// no effect on the HTTP status code because ErrorHandling is set to
+	// ContinueOnError.
+	Registry prometheus.Registerer
+	// If DisableCompression is true, the handler will never compress the
+	// response, even if requested by the client.
+	DisableCompression bool
+	// The number of concurrent HTTP requests is limited to
+	// MaxRequestsInFlight. Additional requests are responded to with 503
+	// Service Unavailable and a suitable message in the body. If
+	// MaxRequestsInFlight is 0 or negative, no limit is applied.
+	MaxRequestsInFlight int
+	// If handling a request takes longer than Timeout, it is responded to
+	// with 503 ServiceUnavailable and a suitable Message. No timeout is
+	// applied if Timeout is 0 or negative. Note that with the current
+	// implementation, reaching the timeout simply ends the HTTP requests as
+	// described above (and even that only if sending of the body hasn't
+	// started yet), while the bulk work of gathering all the metrics keeps
+	// running in the background (with the eventual result to be thrown
+	// away). Until the implementation is improved, it is recommended to
+	// implement a separate timeout in potentially slow Collectors.
+	Timeout time.Duration
+	// If true, the experimental OpenMetrics encoding is added to the
+	// possible options during content negotiation. Note that Prometheus
+	// 2.5.0+ will negotiate OpenMetrics as first priority. OpenMetrics is
+	// the only way to transmit exemplars. However, the move to OpenMetrics
+	// is not completely transparent. Most notably, the values of "quantile"
+	// labels of Summaries and "le" labels of Histograms are formatted with
+	// a trailing ".0" if they would otherwise look like integer numbers
+	// (which changes the identity of the resulting series on the Prometheus
+	// server).
+	EnableOpenMetrics bool
+}
+
+// gzipAccepted returns whether the client will accept gzip-encoded content.
+func gzipAccepted(header http.Header) bool {
+	a := header.Get(acceptEncodingHeader)
+	parts := strings.Split(a, ",")
+	for _, part := range parts {
+		part = strings.TrimSpace(part)
+		if part == "gzip" || strings.HasPrefix(part, "gzip;") {
+			return true
+		}
+	}
+	return false
+}
+
+// httpError removes any content-encoding header and then calls http.Error with
+// the provided error and http.StatusInternalServerError. Error contents is
+// supposed to be uncompressed plain text. Same as with a plain http.Error, this
+// must not be called if the header or any payload has already been sent.
+func httpError(rsp http.ResponseWriter, err error) {
+	rsp.Header().Del(contentEncodingHeader)
+	http.Error(
+		rsp,
+		"An error has occurred while serving metrics:\n\n"+err.Error(),
+		http.StatusInternalServerError,
+	)
+}