Add `--rm` flag to `kubectl debug` to remove debug pod on exit

[tksm]

What would you like to be added:

I would like to add the --rm flag to kubectl debug, similar to the flag in kubectl run and docker run, which allows automatic deletion of the debug pod upon exit. Since ephemeral containers cannot be removed, this flag would only apply when debugging a node or a pod with --copy-to.

I have already opened a PR for this feature, as its implementation is small:
kubernetes/kubernetes#129046

Why is this needed:

kubectl debug -it node is very useful replacement for ssh, but I often forget to remove completed debug pods. These completed pods are generally not useful, and even the official documentation includes a step for "Cleaning up".

$ kubectl get pods
NAME                           READY   STATUS      RESTARTS   AGE
node-debugger-minikube-4gq42   0/1     Completed   0          74s
node-debugger-minikube-8xrvr   0/1     Completed   0          31s
node-debugger-minikube-hscjt   0/1     Completed   0          20s
..

[k8s-ci-robot]

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[ardaguclu]

Although at first sight it looks reasonable, each new flag puts kubectl debug under a risk of unusability that kubectl run already experiences due to plenty of flags. As already stated in the description, this new flag won't work on ephemeral containers anyway. In my opinion, hurting the usability for a new flag far outweighs the benefits we get and we should be reluctant to add this flag.

[tksm]

Hi, I understand that we should be cautious about adding flags. What do you think about adding a specific label to debug pods instead of introducing a flag? This would at least make cleaning up debug pods easier.

[ardaguclu]

Introducing a flag that is only valid for a part of functionality would not be good user experience. Adding a label to manage such flows would be very hacky.

We have decided to reject this request. But if in the future, removal functionality is supported for ephemeral containers (or designed to prohibit this forever?), we may reconsider this decision.

/close

[k8s-ci-robot]

@ardaguclu: Closing this issue.

In response to this:

Introducing a flag that is only valid for a part of functionality would not be good user experience. Adding a label to manage such flows would be very hacky.

We have decided to reject this request. But if in the future, removal functionality is supported for ephemeral containers (or designed to prohibit this forever?), we may reconsider this decision.

/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-sigs/prow repository.

[thuzhf]

@ardaguclu @tksm From a point of view of daily user, I think this flag will be very useful in daily use. And this new flag won't hurt the usability (if it will, the existing so many "--copy-to"-only flags have already hurted a lot, because those flags do not work when user does not use the --copy-to flag...). And thus we really don't need to wait for ephemeral containers' removal functionality to get ready to add this new flag. It is very boresome that I need to delete the debug pod manually everytime. Really hope your team can add this new flag. Please!

[joshua-hancox]

I also wish we could have this 😢 .

If not, surely @ardaguclu suggestion of adding labels is not unreasonable? Then at least we can do kubectl delete pod -l foo=bar with whatever label gets automatically added to debug pods?

When you are working in a big cluster and need to do something on all the nodes, cleaning up the debug pods after is really annoying.