Implement a Devfile Registry operator

[johnmcollier]

What does this PR do?

Fixes devfile/api#190

Implements a DevfileRegistry Kubernetes custom resource and operator using operator-sdk v1.1, based off of the approved design proposal for such an operator.

To make reviewing easier, I've squashed my changes down to 4 commits. If you want to see the original commit history, take a look at https://github.com/johnmcollier/registry-operator.

Overview

In all, this PR does the following:

1. Implementation of a DevfileRegistry custom resource in the registry.devfile.io API group.

   • The fields are based off of the design proposal.
   • Includes the following names/shortnames for the resource:
     • name: DevfileRegistry (case-insensitive)
     • plural: DevfileRegistries (case-insensitive)
     • shortnames: devreg, dr (case-sensitive)

2. Implementation of an operator that manages instances of DevfileRegistry resources and deploys Devfile registries onto a Kubernetes or OpenShift cluster

   • The order in which the Devfile Registry resources are deployed are based off of the design proposal.
   • Supports updating existing DevfileRegistry resources. The default Rolling update strategy is used for the devfile registry deployment to ensure zero-downtime.
   • As well as support for deploying with TLS or persistence enabled/disabled *

3. Simple integration test framework. Based on a pre-existing framework from the devworkspace-operator (see https://github.com/devfile/devworkspace-operator/tree/master/test/e2e).

4. GitHub workflow actions for building and pushing the operator image up to quay.io

* Does not include support for creating secrets with cert-manager at this time, as I've found that the cert-manager API (including the necessary Go types) is not compatible with the versions of the client-go and controller-runtime packages used by operator-sdk.

Directory Structure

• config/

  • Contains the kustomize yaml files for deploying the operator on a Kubernetes
  • These files were generated by the operator-sdk CLI. I only did some minor tweaking by hand where needed (adding labels to the operator deployment, for example.)

• api/v1alpha1/

  • devfileregistry_types.go contans the type definition for the DevfileRegistry custom resource.
  • groupversion_info.go and zz_generated.deepcopy.go are generated/modified by the operator-sdk CLI.

• controllers/

  • Contains the main business logic for the operator (creating/updating resources)
  • Reconcile() in devfileregistry_controller.go is where the bulk of this logic is located.
  • ensure.go ensures that the necessary resources for the devfile registry are deployed on the cluster and up-to-date
  • update.go contains the necessary functions for updating the needed devfile registry resources.

• pkg

  • Helper functions for the operator
  • registry/ functions for generating Kube resource structs (like Deployments, Services, etc) that are then deployed by the operator
  • cluster/ and config/ contains functions for detecting if we're running on OpenShift, and storing that result
    • Borrowed from the devworkspace operator

• tests/integration

  • Integration test code for the operator. Based off of the framework used for the devworkspace operator
  • examples/ contains the yamls used in the tests
  • pkg/tests/: contains the integration tests

How to deploy (OpenShift):

From the root of the repository:

1. Ensure you're logged in to an OpenShift cluster
2. make install && make deploy`
3. oc apply -f registry.yaml
4. oc get dr -w

Testing

• Integration tests (under tests/integration). Can be run with make test-integration. The following scenarios are covered:
  • Simple devfile registry deploy
  • Simple devfile registry deploy with TLS enabled
  • Updating an existing devfile registry instance
• Some unit tests implemented in the pkg/registry package. Can be run with make test.
  • The documentation for unit testing controller-runtime code is quite sparse and good examples are near non-existent, so this is something we'll want to look into.

[GeekArthur]

"DevfileRegistry custom resource" looks good to me, currently I am reviewing "Devfile Registry operator core logic "

[johnmcollier]

@GeekArthur @elsony Thanks for reviewing! I've updated the PR based on your review comments

[GeekArthur]

@johnmcollier Thanks for changes! I already done the review and left some minor comments.

[GeekArthur]

@johnmcollier For me, just change the svc/pvc typo is fine for this PR, we can leave all the refactor/improvement work for the followup PRs. I am gonna approve the PR.

[GeekArthur]

LGTM!

[johnmcollier]

@GeekArthur The if statement refactor's a quick change so I'm gonna update that too when I update the svc typo. Thanks!

[johnmcollier]

@GeekArthur Updated! Mind re-adding the lgtm label if you have no concerns? Thanks!

[GeekArthur]

Re-add LGTM!

[openshift-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: elsony, GeekArthur, johnmcollier
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