[address #4717] create template/metadata when using includeTemplates if not present

[aibarbetta]

Fix #4717

[k8s-ci-robot]

Hi @aibarbetta. Thanks for your PR.

I'm waiting for a kubernetes-sigs member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

I understand the commands that are listed here.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[aibarbetta]

@KnVerey @natasha41575 can you review?

[KnVerey]

/ok-to-test

[KnVerey]

Fix makes sense and regression test is solid. Thank you!

/lgtm
/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: aibarbetta, KnVerey

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

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [KnVerey]

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

[KnVerey]

/hold

[KnVerey]

/unhold

[KnVerey]

Immediately after allowing this to merge I realized a big problem with it: the fieldspec it is updating is not resource-specific, which was only working correctly because of create: false. With this PR, the transformer will add spec.template.metadata.labels to all resources, including ones that don't have that field. For example, if you have a service in the set, you'll get:

kind: Service
metadata:
  labels:
    app: bingo
    owner: alice
    someName: someValue
  name: svc
spec:
  template:
    metadata:
      labels:
        app: bingo
        owner: alice
        someName: someValue

which is invalid. We need to be merging complete, resource-specific fieldspecs. I'm going to revert this PR.

[wolfmah]

Yeah, that's why commonLabels adds them all separately in its field specs definition: api/konfig/builtinpluginconsts/commonlabels.go.

The idea would be take all the spec from commonLabels, that are not relevant to selectors, to the includeTemplates:

List of relevant specs

- path: metadata/labels
  create: true

- path: spec/template/metadata/labels
  create: true
  version: v1
  kind: ReplicationController

- path: spec/template/metadata/labels
  create: true
  kind: Deployment

- path: spec/template/metadata/labels
  create: true
  kind: ReplicaSet

- path: spec/template/metadata/labels
  create: true
  kind: DaemonSet

- path: spec/template/metadata/labels
  create: true
  group: apps
  kind: StatefulSet

- path: spec/volumeClaimTemplates[]/metadata/labels
  create: true
  group: apps
  kind: StatefulSet

- path: spec/template/metadata/labels
  create: true
  group: batch
  kind: Job

- path: spec/jobTemplate/metadata/labels
  create: true
  group: batch
  kind: CronJob

- path: spec/jobTemplate/spec/template/metadata/labels
  create: true
  group: batch
  kind: CronJob

I don't really know what would be the best way to sync those two together, or even how to implement a naive copy/paste version, but IMHO the high level of what needs to be done is that.