Preloading Functions for Distribution¶

OpenFaaS Edge is licensed for distribution of bespoke solutions to end customers. The product itself can shipped as a convenient DEB/RPM package, or pre-installed in a VM image.

But when it comes to functions, you generally have to deploy these via faas-cli.

Preloading is a solution to this problem.

On the first boot of the faasd-provider service, any OpenFaaS Stack YAML files found will be deployed automatically.

So before you install OpenFaaS Edge, create the: /var/lib/faasd-provider/functions folder, and place any number of OpenFaaS function YAML files within it.

This is designed for an initial deployment of a set of functions when shipping a product to an end customer.

To update existing functions or to deploy new ones after the initial preload, you have two options:

Use faas-cli deploy
Remove /var/lib/faasd-provider/bootstrap.ran and restart the faasd-provider service.

To delete functions which were previously deployed via preloading, use faas-cli remove. Removing them from the /var/lib/faasd-provider/functions folder will have no effect.

Secrets for preloaded functions¶

If any of your functions require secrets, make sure you pre-create the secrets folder: /var/lib/faasd-provider/secrets.

Then create functions in a folder that matches the destination namespace, so for a secret named api-key in openfaas-fn:

mkdir -p /var/lib/faasd-provider/secrets/openfaas-fn
echo "secret" | sudo tee /var/lib/faasd-provider/secrets/openfaas-fn/api-key

A single stack.yaml¶

You can ship a single stack.yaml file with all your functions defined separately within it.

stack.yaml

provider:
  name: openfaas

functions:
  env:
    image: ghcr.io/openfaas/alpine:latest
    fprocess: env
  nodeinfo:
    image: ghcr.io/openfaas/nodeinfo:latest

You can leave in build data such as the template and handler folder, or you can trim it away for brevity. It won't be used at deployment time.

Copy the files to the destination:

sudo mkdir -p /var/lib/faasd-provider/functions/
sudo cp stack.yaml /var/lib/faasd-provider/functions/

Multiple YAML files¶

You could also create multiple YAML files - one per function:

env.yaml

provider:
  name: openfaas

functions:
  env:
    image: ghcr.io/openfaas/alpine:latest
    fprocess: env

nodeinfo.yaml

provider:
  name: openfaas

functions:
  nodeinfo:
    image: ghcr.io/openfaas/nodeinfo:latest
    fprocess: nodeinfo

Copy the files to the destination:

sudo mkdir -p /var/lib/faasd-provider/functions/
sudo cp nodeinfo.yaml /var/lib/faasd-provider/functions/
sudo cp env.yaml /var/lib/faasd-provider/functions/

Running the preload a second time¶

By default, the preload will only run once, then a file is written out to prevent it from running again.

To have the preload run a second time i.e. during testing, simply remove the run file: sudo rm -rf /var/lib/faasd-provider/bootstrap.ran.