Promote kubectl debug to GA

[ardaguclu]

• One-line PR description: This PR promotes kubectl debug to stable. In reality, this promotion seems like a more paperwork because kubectl debug has been used for nearly more than 3 years and this is a sufficient time to collect feedback, incorporate changes and add unit, integration tests(https://github.com/kubernetes/kubernetes/blob/master/test/cmd/debug.sh)

• Issue link: KEP 1441 - kubectl debug #1441

• Other comments:

[soltysh]

One minor nit, can you update the format (mostly the questions in PRR) with the template https://github.com/kubernetes/enhancements/blob/master/keps/NNNN-kep-template/README.md

[soltysh]

Did a quick google search and I got (in no particular order):

• https://collabnix.com/debug-your-kubernetes-applications-made-easy-with-kubectl-debug-tool/
• https://www.linkedin.com/pulse/debug-kubernetes-applications-kubectl-cuong-nguyen-duc
• https://medium.com/datamindedbe/debugging-running-pods-on-kubernetes-2ba160c47ef5

[ardaguclu]

Thanks a lot. Updated with the links above.

[soltysh]

/lgtm
/approve
for sig-cli

[soltysh]

/label tide/merge-method-squash

[enj]

PRR shadow

This LGTM, I think most of PRR does not really apply to kubectl debug. Since this whole flow is user initiated, there really aren't any novel concerns that are unique to kubectl debug that wouldn't apply equally to just using the REST API directly. Most of these pods are likely short lived so I see no significant concerns around resource consumption.

[johnbelamaric]

/approve

@enj Yes, we see that with lots of the kubectl things, often many questions don't really apply.

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: ardaguclu, johnbelamaric, soltysh

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:

• keps/prod-readiness/OWNERS [johnbelamaric]
• keps/sig-cli/OWNERS [johnbelamaric,soltysh]

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