KEP-5307 Initial KEP for container restart policy

[yuanwang04]

• One-line PR description: Initial KEP for container restart policy

• Issue link: Container restart rules to customize the pod restart policy #5307

• Other comments: Discussion link https://docs.google.com/document/d/13fQu343OBEM2ICHLXfWHrApmzskd4nY3xWI27EbMJyI/edit?tab=t.0

[k8s-ci-robot]

Welcome @yuanwang04!

It looks like this is your first PR to kubernetes/enhancements 🎉. Please refer to our pull request process documentation to help your PR have a smooth ride to approval.

You will be prompted by a bot to use commands during the review process. Do not be afraid to follow the prompts! It is okay to experiment. Here is the bot commands documentation.

You can also check if kubernetes/enhancements has its own contribution guidelines.

You may want to refer to our testing guide if you run into trouble with your tests not passing.

If you are having difficulty getting your pull request seen, please follow the recommended escalation practices. Also, for tips and tricks in the contribution process you may want to read the Kubernetes contributor cheat sheet. We want to make sure your contribution gets all the attention it needs!

Thank you, and welcome to Kubernetes. 😃

[k8s-ci-robot]

Hi @yuanwang04. Thanks for your PR.

I'm waiting for a kubernetes 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-sigs/prow repository.

[SergeyKanzhelev]

@dchen1107 I remember you had a concern with having Never pod with the container inside it that has restart count increasing. How strong is this concern? Strong enough to iontroduce the restartPolicy: Custom?

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: yuanwang04
Once this PR has been reviewed and has the lgtm label, please assign johnbelamaric for approval. For more information see the Code Review Process.

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

Needs approval from an approver in each of these files:

• keps/prod-readiness/OWNERS
• keps/sig-node/OWNERS

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

[kannon92]

/ok-to-test

[kannon92]

This API is at the container level it seems.

[yuanwang04]

Yes, just mentioning it here since there are some discussion around whether we need to introduce another pod-level restart policy #5308 (comment)

[kerthcet]

A big concern is once we introduced pod-level restart policy, how to interact with job failure policy? Maybe not today.

[kannon92]

How does this interact with PodFailurePolicy?

[yuanwang04]

Added discussion around Job's PodFailurePolicy. Basically, this shouldn't affect how Job handles pod failures. Job only checks container exit codes (for PodFailurePolicy) when the Pod finished (and restartPolicy=Never). However, if the container is restarted by the proposed container restart policy, the pod will still be Running, and Job controller will not kick in.