faasd - serverless with containerd

faasd is a Golang supervisor that bundles OpenFaaS for use with containerd instead of a container orchestrator like Kubernetes or Docker Swarm.

About faasd:

• faasd is a single Golang binary
• faasd is multi-arch, so works on x86_64, armhf and arm64
• faasd downloads, starts and supervises the core components to run OpenFaaS

What does faasd deploy?

• faas-containerd
• Prometheus
• the OpenFaaS gateway

You can use the standard faas-cli with faasd along with pre-packaged functions in the Function Store, or build your own with the template store.

faas-containerd supports:

• faas list
• faas describe
• faas deploy --update=true --replace=false
• faas invoke
• faas invoke --async

Other operations are pending development in the provider.

Pre-reqs

• Linux

  PC / Cloud - any Linux that containerd works on should be fair game, but faasd is tested with Ubuntu 18.04

  For Raspberry Pi Raspbian Stretch or newer also works fine

  For MacOS users try multipass.run or Vagrant

  For Windows users, install Git Bash along with multipass or vagrant. You can also use WSL1 or WSL2 which provides a Linux environment.

• Installation steps as per faas-containerd for building and for development

  • netns binary in $PATH
  • containerd v1.3.2

• faas-cli (optional)

Backlog

Pending:

• Use CNI to create network namespaces and adapters
• Monitor and restart any of the core components at runtime if the container stops
• Bundle/package/automate installation of containerd - see bootstrap from k3s
• Provide ufw rules / example for blocking access to everything but a reverse proxy to the gateway container
• Provide simple Caddyfile example in the README showing how to expose the faasd proxy on port 80/443 with TLS

Done:

• Inject / manage IPs between core components for service to service communication - i.e. so Prometheus can scrape the OpenFaaS gateway - done via /etc/hosts mount
• Add queue-worker and NATS
• Create faasd.service and faas-containerd.service
• Self-install / create systemd service via faasd install
• Restart containers upon restart of faasd
• Clear / remove containers and tasks with SIGTERM / SIGINT
• Determine armhf/arm64 containers to run for gateway
• Configure basic_auth to protect the OpenFaaS gateway and faas-containerd HTTP API

Tutorial: Get started on armhf / Raspberry Pi

You can run this tutorial on your Raspberry Pi, or adapt the steps for a regular Linux VM/VPS host.

• faasd - lightweight Serverless for your Raspberry Pi

Hacking (build from source)

First run faas-containerd

cd $GOPATH/src/github.com/alexellis/faas-containerd

# You'll need to install containerd and its pre-reqs first
# https://github.com/alexellis/faas-containerd/

sudo ./faas-containerd

Then run faasd, which brings up the gateway and Prometheus as containers

cd $GOPATH/src/github.com/alexellis/faasd
go build

# Install with systemd
# sudo ./faasd install

# Or run interactively
# sudo ./faasd up

Build and run (binaries)

# For x86_64
sudo curl -fSLs "https://github.com/alexellis/faasd/releases/download/0.4.2/faasd" \
    -o "/usr/local/bin/faasd" \
    && sudo chmod a+x "/usr/local/bin/faasd"

# armhf
sudo curl -fSLs "https://github.com/alexellis/faasd/releases/download/0.4.2/faasd-armhf" \
    -o "/usr/local/bin/faasd" \
    && sudo chmod a+x "/usr/local/bin/faasd"

# arm64
sudo curl -fSLs "https://github.com/alexellis/faasd/releases/download/0.4.2/faasd-arm64" \
    -o "/usr/local/bin/faasd" \
    && sudo chmod a+x "/usr/local/bin/faasd"

At run-time

Look in hosts in the current working folder to get the IP for the gateway or Prometheus

127.0.0.1       localhost
172.19.0.1      faas-containerd
172.19.0.2      prometheus

172.19.0.3      gateway
172.19.0.4      nats
172.19.0.5      queue-worker

Since faas-containerd uses containerd heavily it is not running as a container, but as a stand-alone process. Its port is available via the bridge interface, i.e. netns0.

• Prometheus will run on the Prometheus IP plus port 8080 i.e. http://172.19.0.2:9090/targets

• faas-containerd runs on 172.19.0.1:8081

• Now go to the gateway's IP address as shown above on port 8080, i.e. http://172.19.0.3:8080 - you can also use this address to deploy OpenFaaS Functions via the faas-cli.

• basic-auth

  You will then need to get the basic-auth password, it is written to $GOPATH/src/github.com/alexellis/faasd/basic-auth-password if you followed the above instructions. The default Basic Auth username is admin, which is written to $GOPATH/src/github.com/alexellis/faasd/basic-auth-user, if you wish to use a non-standard user then create this file and add your username (no newlines or other characters)

Installation with systemd

• faasd install - install faasd and containerd with systemd, run in $GOPATH/src/github.com/alexellis/faasd
• journalctl -u faasd - faasd systemd logs
• journalctl -u faas-containerd - faas-containerd systemd logs

Appendix

Removing containers:

echo faas-containerd gateway prometheus | xargs sudo ctr task rm -f

echo faas-containerd gateway prometheus | xargs sudo ctr container rm

echo faas-containerd gateway prometheus | xargs sudo ctr snapshot rm

Links

31968e4b48/cmd/network.go

c4f62c86bd/catraia-net/network.go

https://github.com/containernetworking/plugins

https://github.com/containerd/go-cni