Add support for repeated PVC-claim but using subPath in AA-validation

[jlpettersson]

Changes

The validation for compatibility with the Affinity Assistant does not
support the same PVC repeated, but using different subPaths.

This patch adds support for this case.

Closes #3085
/kind bug

Submitter Checklist

These are the criteria that every PR should meet, please check them off as you
review them:

• Includes tests (if functionality changed/added)
• Includes docs (if user facing)
• Commit messages follow commit message best practices
• Release notes block has been filled in or deleted (only if no user facing changes)

See the contribution guide for more details.

Double check this list of stuff that's easy to miss:

• If you are adding a new binary/image to the cmd dir, please update
  the release Task to build and release this image.

Reviewer Notes

If API changes are included, additive changes must be approved by at least two OWNERS and backwards incompatible changes must be approved by more than 50% of the OWNERS, and they must first be added in a backwards compatible way.

Release Notes

Fixes a bug with validation for the Affinity Assistant when the same PVC is used for
multiple workspaces but with different subPaths

[tekton-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by:
To complete the pull request process, please assign bobcatfish
You can assign the PR to them by writing /assign @bobcatfish in a comment when ready.

The full list of commands accepted by this bot can be found here.

Needs approval from an approver in each of these files:

• OWNERS

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[tekton-robot]

The following is the coverage report on the affected files.
Say /test pull-tekton-pipeline-go-coverage to re-run this coverage report

File	Old Coverage	New Coverage	Delta
pkg/reconciler/taskrun/taskrun.go	78.3%	78.4%	0.1

[jlpettersson]

I'll leave this as a draft for now - since I have not implemented any test case for this case. I feel it is a bit heavy to add a complete new test case for this case - so the test may need refactoring. Feel free to add test case if anyone feel this fix is in hurry.

[bitsofinfo]

will take it with or without a test! :) don't want to be stuck in 0.14.3, haha

[ghost]

I'll leave this as a draft for now - since I have not implemented any test case for this case. I feel it is a bit heavy to add a complete new test case for this case - so the test may need refactoring. Feel free to add test case if anyone feel this fix is in hurry.

My suggestion would be to move the validation bit into pkg/workspace/validate.go and move the annotation check into the prepare() func of the reconciler. So that would look something like this:

	// pkg/reconciler/taskrun/taskrun.go
	// after workspace.ValidateBindings() is called in prepare()
	_, isAssociatedWithAnAffinityAssistant := tr.Annotations[workspace.AnnotationAffinityAssistantName]
	if isAssociatedWithAnAffinityAssistant {
		if err := workspace.ValidateOnlyOnePVCBindingUsed(tr.Spec.Workspaces); err != nil {
			logger.Errorf("TaskRun %q workspaces are invalid: %v", tr.Name, err)
			tr.Status.MarkResourceFailed(podconvert.ReasonFailedValidation, err)
			return nil, nil, controller.NewPermanentError(err)
		}
	}

// pkg/workspace/validate.go
func ValidateOnlyOnePVCBindingUsed(wbs []v1beta1.WorkspaceBinding) error {
	workspaceVolumes := make(map[string]bool)
	for _, w := range wbs {
		if w.PersistentVolumeClaim != nil {
			workspaceVolumes[w.PersistentVolumeClaim.ClaimName] = true
		}
		if w.VolumeClaimTemplate != nil {
			workspaceVolumes[w.Name] = true
		}
	}

	if len(workspaceVolumes) > 1 {
		return fmt.Errorf("TaskRun mounts more than one ...") // cut for brevity
	}
	return nil
}

Then ValidateOnlyOnePVCBindingUsed can be tested in isolation in pkg/workspace/validate_test.go. @jlpettersson are you happy with this suggestion? I can implement it and push to this PR tomorrow if you agree with the direction.

[jlpettersson]

@sbwsg sounds good to me

[ghost]

Updated as described and opened #3099