faasd/docs/ROADMAP.md

faasd backlog and features

Supported operations

• faas login
• faas up
• faas list
• faas describe
• faas deploy --update=true --replace=false
• faas invoke --async
• faas invoke
• faas rm
• faas store list/deploy/inspect
• faas version
• faas namespace
• faas secret
• faas logs
• faas auth - supported for Basic Authentication and OpenFaaS PRO with OIDC and Single-sign On.

Scale from and to zero is also supported. On a Dell XPS with a small, pre-pulled image unpausing an existing task took 0.19s and starting a task for a killed function took 0.39s. There may be further optimizations to be gained.

Constraints vs OpenFaaS on Kubernetes

faasd suits certain use-cases as mentioned in the README file, for those who want a solution which can scale out horizontally with minimum effort, Kubernetes or K3s is a valid option.

One replica per function

Functions only support one replica, so cannot scale horizontally, but can scale vertically.

Workaround: deploy one uniquely named function per replica.

Scale from zero may give a non-200

When scaling from zero there is no health check implemented, so the request may arrive before your HTTP server is ready to serve a request, and therefore give a non-200 code.

Workaround: Do not scale to zero, or have your client retry HTTP calls.

No clustering is available

No clustering is available in faasd, however you can still apply fault-tolerance and high availability techniques.

Workaround: deploy multiple faasd instances and use a hardware or software load-balancer. Take regular VM/host snapshots or backups.

No rolling updates

When running faas-cli deploy, your old function is removed before the new one is started. This may cause a small amount of downtime, depending on the timeouts and grace periods you set.

Workaround: deploy uniquely named functions per version, and switch an Ingress or Reverse Proxy record to point at a new version once it is ready.

Known issues

Non 200 HTTP status from the gateway upon first use

This issue appears to happen sporadically and only for some users.

If you get a non 200 HTTP code from the gateway, or caddy after installing faasd, check the logs of faasd:

sudo journalctl -t faasd

If you see the following error:

unable to dial to 10.62.0.5:8080, error: dial tcp 10.62.0.5:8080: connect: no route to host

Restart the faasd service with:

sudo systemctl restart faasd

Backlog

Should have:

• Resolve core services from functions by populating/sharing /etc/hosts between faasd and faasd-provider
• Docs or examples on how to use the various connectors and connector-sdk
• Monitor and restart any of the core components at runtime if the container stops
• Asynchronous deletion instead of synchronous

Nice to Have:

• Terraform for AWS (in-progress)
• Total memory limits - if a node has 1GB of RAM, don't allow more than 1000MB of RAM to be reserved via limits
• Offer live rolling-updates, with zero downtime - requires moving to IDs vs. names for function containers
• Multiple replicas per function

Completed

• Provide a cloud-init configuration for faasd bootstrap
• Configure core services from a docker-compose.yaml file
• Store and fetch logs from the journal
• Add support for using container images in third-party public registries
• Add support for using container images in private third-party registries
• Provide a cloud-config.txt file for automated deployments of faasd
• 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 faasd-provider.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 faasd-provider HTTP API
• Setup custom working directory for faasd /var/lib/faasd/
• Use CNI to create network namespaces and adapters
• Optionally expose core services from the docker-compose.yaml file, locally or to all adapters.
• containerd can't pull image from Github Docker Package Registry ghcr.io support
• Provide simple Caddyfile example in the README showing how to expose the faasd proxy on port 80/443 with TLS
• Annotation support
• Hard memory limits for functions
• Terraform for DigitalOcean
• Store and retrieve annotations in function spec - in progress
• An installer for faasd and dependencies - runc, containerd