Update labels to use kubernetes recommended labels

[therealdwright]

What does this PR do?

Kubernetes have not used the app or k8s-app for some time
and have provided guidance on what the recommended labels are
for some time as seen in their docs.

This commit updates all manifests/docs to use this approach.

Why is it important?

Users who choose to adopt kubernetes label best practises will not have to fork elastic manifests and can instead rely on the upstream ones directly.

Checklist

• My code follows the style guidelines of this project
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have made corresponding change to the default configuration files
• I have added tests that prove my fix is effective or that my feature works
• I have added an entry in ./changelog/fragments using the changelog tool
• I have added an integration test or an E2E test

Disruptive User Impact

Users will need to upgrade using kubectl replace as some of the labels are immutable

[cla-checker-service]

💚 CLA has been signed

[mergify]

This pull request does not have a backport label. Could you fix it @therealdwright? 🙏
To fixup this pull request, you need to add the backport labels for the needed
branches, such as:

• backport-v./d./d./d is the label to automatically backport to the 8./d branch. /d is the digit

NOTE: backport-skip has been added to this pull request.

[elasticmachine]

Pinging @elastic/elastic-agent-control-plane (Team:Elastic-Agent-Control-Plane)

[gizas]

Looks good!

[blakerouse]

Definitely need a changelog entry for this change, as this affects users.

[pierrehilbert]

@therealdwright Thanks for your contribution and signing the CLA.
As @blakerouse mentioned, could you please add de changelog entry to let our users be aware of this change?

[therealdwright]

could you please add de changelog entry to let our users be aware of this change?

I've pushed a change log entry as requested.

[blakerouse]

Thanks for the changelog.

[therealdwright]

@blakerouse I have rebased on main as the SonarQube Code Analysis and buildkite/elastic-agent were stuck in waiting for status to be reported. LMK if this is something maintainers must manually trigger.

[blakerouse]

@therealdwright Yes it requires an authorized user to approve and run the workflows. This ensures we can review the change before we allow it to run on an actual machine.

[ycombinator]

buildkite test this

[ycombinator]

buildkite test this

[ycombinator]

CI failures look relevant: https://buildkite.com/elastic/elastic-agent/builds/9028#018f97b0-430e-4777-9267-e618e45b3341/512

[therealdwright]

CI failures look relevant

How do contributors get access to CI logs?

[ycombinator]

CI failures look relevant

How do contributors get access to CI logs?

Oops, sorry about that, @therealdwright! Here are the logs that are relevant:

diff --git a/deploy/kubernetes/elastic-agent-managed-kubernetes.yaml b/deploy/kubernetes/elastic-agent-managed-kubernetes.yaml
--
  | index 074a15daa1..b54834c313 100644
  | a/deploy/kubernetes/elastic-agent-managed-kubernetes.yaml | 0s
  | b/deploy/kubernetes/elastic-agent-managed-kubernetes.yaml | 0s
  | @@ -212,7 +212,7 @@ kind: ClusterRole
  | metadata:
  | name: elastic-agent
  | labels:
  | -    app.kubernetes.io/name.kubernetes.io/name: elastic-agent
  | +    app.kubernetes.io/name: elastic-agent
  | rules:
  | - apiGroups: [""]
  | resources:
  | @@ -284,7 +284,7 @@ metadata:
  | # Should be the namespace where elastic-agent is running
  | namespace: kube-system
  | labels:
  | -    app.kubernetes.io/name.kubernetes.io/name: elastic-agent
  | +    app.kubernetes.io/name: elastic-agent
  | rules:
  | - apiGroups:
  | - coordination.k8s.io
  | @@ -298,7 +298,7 @@ metadata:
  | name: elastic-agent-kubeadm-config
  | namespace: kube-system
  | labels:
  | -    app.kubernetes.io/name.kubernetes.io/name: elastic-agent
  | +    app.kubernetes.io/name: elastic-agent
  | rules:
  | - apiGroups: [""]
  | resources:
  | @@ -313,5 +313,5 @@ metadata:
  | name: elastic-agent
  | namespace: kube-system
  | labels:
  | -    app.kubernetes.io/name.kubernetes.io/name: elastic-agent
  | +    app.kubernetes.io/name: elastic-agent
  | ---
  | deploy/kubernetes/elastic-agent-managed-kubernetes.yaml: needs update
  | make[1]: *** [Makefile:59: check-no-changes] Error 1
  | make[1]: Leaving directory '/opt/buildkite-agent/builds/bk-agent-prod-gcp-1716236865505762234/elastic/elastic-agent'
  | make: *** [Makefile:40: check-ci] Error 2

To fix that, I ran make generate-k8s from the deploy/kubernetes folder and pushed up 04de6e6 with the changes.

[ycombinator]

buildkite test this

[elastic-sonarqube]

Quality Gate passed

Issues
0 New issues
0 Fixed issues
0 Accepted issues

Measures
0 Security Hotspots
No data about Coverage
No data about Duplication

See analysis details on SonarQube