KEP-127: Update userns KEP template to latest and and answer more sections

[rata]

This just updates to the new KEP template and check the documentation and design doc boxes we have done for a long time already.

cc @haircommander @mrunalp @giuseppe

• One-line PR description: Update the KEP template and check some boxes (documentation and design doc) we have done for years now

• Issue link: http://kep.k8s.io/127

• Other comments:

[haircommander]

/lgtm

[kannon92]

I think you still need more items to fill out.

Release Signoff Checklist is missing subbullets for Test plan is in place, giving consideration to SIG Architecture and SIG Testing input (including test refactors) and Graduation criteria is in place
Missing response for Risks and Mitigations
Missing response for Prerequisite testing updates
Missing response for What steps should be taken if SLOs are not being met to determine the problem?
No Drawbacks but this is not vital

[rata]

@kannon92 thanks for the review!

Release Signoff Checklist is missing subbullets for Test plan is in place, giving consideration to SIG Architecture and SIG Testing input (including test refactors) and Graduation criteria is in place

It is added on this PR.

Missing response for Risks and Mitigations
Missing response for Prerequisite testing updates

Will add, thanks!

Missing response for What steps should be taken if SLOs are not being met to determine the problem?

This is needed for GA the comments on the template say. I can't link to that part, as the markdown comment can only be seen with the raw file, but here is what it says:

> 
<!--
This section must be completed when targeting beta to a release.

For GA, this section is required: approvers should be able to confirm the
previous answers based on experience in the field.

The Troubleshooting section currently serves the `Playbook` role. We may consider
splitting it into a dedicated `Playbook` document (potentially with some monitoring
details). For now, we leave it here.
-->

We are not targetting GA, so I'm not planning to add this. Or am I missing something?

EDIT: oh, I now see it should be filled for beta but it is required for GA. I can sketch something, but is it required or not, then?

[rata]

Okay, I've been doing some digging and I know how to fill that part that part. So I'll fill it up now, and continue with the rest. Thanks!

[rata]

Pushed new version with those sections. PTAL!

cc @haircommander :)

[kannon92]

Thank you for the updates.

It would be worth answering these questions from an admin standpoint.

https://github.com/kubernetes/enhancements/blob/72fffde58403123c4ac6ac3c689f05edbdd1668a/keps/sig-node/127-user-namespaces/README.md#monitoring-requirements

Given the interest in user namespaces, the answer seems to focus on user workloads and not really answering the question on how an operator would actually know if people are using this feature. Remember there can be many namespaces and an operator would most likely look at metrics to see this info. They would probably not look at each and every pod spec.

I am bringing it up here as we start moving usernamespace to feature gate on we should think through these questions as it does get harder to change as more people start using usernamespaces.

[wojtek-t]

/lgtm
From PRR perspective

[rata]

@wojtek-t great, thanks!

@kannon92 Feel free to reach out to me on the k8s slack, I'm rata there too. We can talk about it and see if there is something we can agree on. Also, adding a metric is not something hard to change, so I don't think there is urgency to do it for this release.

@haircommander I guess this still LGTY? The deadline is quite close, it would be great to merge this :-)

[haircommander]

yeah still
/lgtm
I agree let's think about metrics but we don't need to address here right now

[rata]

@mrunalp @haircommander the KEP is at risk because this PR is not merged. It will be great to merge ASAP

[k8s-ci-robot]

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