# faasd - serverless with containerd

[![Build Status](https://travis-ci.com/alexellis/faasd.svg?branch=master)](https://travis-ci.com/alexellis/faasd)

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](https://github.com/alexellis/faas-containerd/)
* [Prometheus](https://github.com/prometheus/prometheus)
* [the OpenFaaS gateway](https://github.com/openfaas/faas/tree/master/gateway)

You can use the standard [faas-cli](https://github.com/openfaas/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 - ideally Ubuntu, which is used for testing
* Installation steps as per [faas-containerd](https://github.com/alexellis/faas-containerd) for building and for development
    * [netns](https://github.com/genuinetools/netns/releases) binary in `$PATH`
    * [containerd v1.3.2](https://github.com/containerd/containerd)
* [faas-cli](https://github.com/openfaas/faas-cli) (optional)

## Backlog

Pending:

* [ ] Configure `basic_auth` to protect the OpenFaaS gateway and faas-containerd HTTP API
* [ ] 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](https://github.com/rancher/k3s)
* [ ] Provide ufw rules / example for blocking access to everything but a reverse proxy to the gateway container

Done:

* [x] 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
* [x] Add queue-worker and NATS
* [x] Create faasd.service and faas-containerd.service
* [x] Self-install / create systemd service via `faasd install`
* [x] Restart containers upon restart of faasd
* [x] Clear / remove containers and tasks with SIGTERM / SIGINT
* [x] Determine armhf/arm64 containers to run for gateway

## Hacking (build from source)

First run faas-containerd

```sh
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

```sh
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)

```sh
# For x86_64
sudo curl -fSLs "https://github.com/alexellis/faasd/releases/download/0.2.5/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/0.2.5/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/0.2.5/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

```sh
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`. 

#### 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:

```sh
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

https://github.com/renatofq/ctrofb/blob/31968e4b4893f3603e9998f21933c4131523bb5d/cmd/network.go

https://github.com/renatofq/catraia/blob/c4f62c86bddbfadbead38cd2bfe6d920fba26dce/catraia-net/network.go

https://github.com/containernetworking/plugins

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