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 - ideally Ubuntu, which is used for testing
• Installation steps as per faas-containerd for building and for development
  • netns binary in $PATH
  • containerd v1.3.2
• 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
• Provide ufw rules / example for blocking access to everything but a reverse proxy to the gateway container

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

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/0.2.2/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/0.2.2/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/0.2.2/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.

Installation with systemd

• faasd install - install faasd and containerd with systemd
• 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