danbev / js-function-operator

R&P for an operator to deploy and execute Node.js functions as Knative Services on Kubernetes

JSFunction Operator

A Kubernetes Operator for JavaScript functions

This project provides a Kubernetes Operator for managing a JSFunction custom resource. A JSFunction accepts a JavaScript function inline, as well as an optional inline pakcage.json.

When a JSFunction resource is applied to a cluster, the controller takes the following steps during reconciliation.

• Check to see if a Knative Service for this function exists. If not, create one.
• Create a ConfigMap containing with the user supplied data (index.js/package.json)
• Create a TaskRun, installing any dependencies and building a runtime image using lanceball/js-runtime
• Create a PodSpec for the Service specifying the runtime image just created
• Wires up knative eventing, if events is set to true in a JSFunction custom resource. Knative Eventing objects Subscription and Channel are created and acts as a sink for the function. Events sent to the Channel are passed to the function.

This is still in early stages of development and may change rapidly.

Running the operator

This project has been developed using OpenShift 4.x - both on an AWS cluster, as well as with Code Ready Containers. To run it in your environment, you can either use operator-sdk up local for testing, or deploy using operator.yaml.

Operator dependencies

The project uses Knative Serving and Eventing, as well as OpenShift Pipelines. Be sure you have these installed in your namespace.

Deploy the operator

Be sure you are logged in to your cluster, then run the following commands.

./deploy/deploy.sh

This will set up a service account with appropriate roles, add the JSFunction type and a build Task for the function, and finally deploy the operator to the current namespace.

Note privileges for the service account

Among the things that happen when a new JSFunction is created, is that a build task involving the creation of runtime images runs. This requires permissions not available by default on OpenShift. These permissions are added to the js-function-operator service account with the following commands when you run ./deploy/deploy.sh.

oc adm policy add-role-to-user edit -z js-function-operator
oc adm policy add-scc-to-user privileged -z js-function-operator

To deploy a function, run

kubectl apply -f deploy/crds/faas_v1alpha1_jsfunction_cr.yaml

Testing the Knative Eventing wiring

Set events to true in a JSFunction custom resource and deploy this CR.

To emit events to the automatically created Channel, run command specified below. This will emit event every minute.

kubectl apply -f hack/cronjob-source.yaml