add feature gate ControllerManagerLeaderMigration

[jiahuif]

What type of PR is this?

/kind feature

What this PR does / why we need it:

This PR is split from 96541 that add the required feature gate of KEP-2436 (kubernetes/enhancements#2436)
The reason of splitting is that changes to features have different owners than the original PR.

Special notes for your reviewer:

NONE

Additional documentation e.g., KEPs (Kubernetes Enhancement Proposals), usage docs, etc.:

• KEP: https://github.com/kubernetes/enhancements/tree/master/keps/sig-cloud-provider/2436-controller-manager-leader-migration

# https://github.com/kubernetes/enhancements/blob/d7f1a349bd377e1a476e5634c27933139fd0fafe/keps/sig-cloud-provider/2436-controller-manager-leader-migration/kep.yaml#L39

# List the feature gate name and the components for which it must be enabled
feature-gates:
  - name: ControllerManagerLeaderMigration
    components:
      - cloud-controller-manager
      - kube-controller-manager
disable-supported: true

[k8s-ci-robot]

@jiahuif: This issue is currently awaiting triage.

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[jiahuif]

/sig cloud-provider
/priority important-soon
/assign @jpbetz @cheftako

[jiahuif]

/assign @andrewsykim
for feature approval of SIG Cloud Provider

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: jiahuif
To complete the pull request process, please assign andrewsykim after the PR has been reviewed.
You can assign the PR to them by writing /assign @andrewsykim 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:

• pkg/features/OWNERS

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

[jpbetz]

/lgtm

[jpbetz]

/assign @andrewsykim

[jpbetz]

@thockin any chance we could get you to approve this? I think @andrewsykim is unavailable. It's already got SIG stamp of approval via the KEP.

[cheftako]

Should also be in kubernetes/staging/src/k8s.io/controller-manager/pkg/features/kube_features.go

[jpbetz]

@liggitt would you be willing to approve? It's just the feature gate approved in the KEP

[liggitt]

@liggitt would you be willing to approve? It's just the feature gate approved in the KEP

both @cheftako and @andrewsykim should be in https://github.com/kubernetes/kubernetes/blob/master/OWNERS_ALIASES#L537-L538 per https://github.com/kubernetes/community/tree/master/sig-cloud-provider#chairs, which would let them approve this on behalf of sig-cloud-provider

[jiahuif]

We won't need this feature gate to be k8s-wide for now. I will re-open it if it needs to be global in the future.

/lgtm cancel
/close

[k8s-ci-robot]

@jiahuif: Closed this PR.

In response to this:

We won't need this feature gate to be k8s-wide for now. I will re-open it if it needs to be global in the future.

/lgtm cancel
/close

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.

[jiahuif]

The feature gate is added here instead

kubernetes/staging/src/k8s.io/controller-manager/pkg/features/kube_features.go

Lines 54 to 58 in 2f263b2

	// owner: @jiahuif
	// alpha: v1.21
	//
	// Enables Leader Migration for kube-controller-manager and cloud-controller-manager
	ControllerManagerLeaderMigration featuregate.Feature = "ControllerManagerLeaderMigration"