Trigger PRR for kep 4369

[HirazawaUi]

• One-line PR description: Trigger PRR for kep 4369

• Issue link: Allow almost all printable ASCII characters in environment variables #4369

• Other comments:

[k8s-ci-robot]

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[HirazawaUi]

/cc @thockin

[thockin]

I am not a PRR approver.

@johnbelamaric @deads2k @jpbetz @wojtek-t

This one will hopefully be easy - "Allow almost all printable ASCII characters in environment variables"

[deads2k]

@jpbetz volunteered for this one.

[jpbetz]

I can review for PRR. Go ahead and swap my name in here.

Since this is targeting alpha, we don't need all the PRR sections complete. But I did notice that they have all been filled out, so I looked them over. "Monitoring Requirements" is marked as "N/A". I'd be okay with addressing this in Beta, but I think there are monitoring needs. @deads2k pointed out to me that kubelet/CRI implementations could fail on pods using this enhancement and we should be able to detect and monitor that (is there a metric that exists today that we can show surfaces this sort of problem?). Can we update the "Monitoring Requirements" to reflect that we will look into this in Beta and add a note to the graduation criteria?

We should also include (for GA) some "Troubleshooting" details for how to deal with incompatible kubelet/CRI implementations.

I also agree with the concerns in #4373 (comment)). We should articulate in the KEP somewhere what our "beta time duration" is going to be. A change like this limits v1 pods portability between clusters to those that are in a compatible version range, so I'd like that range to be sufficiently wide (all supported versions?) before GA.

[HirazawaUi]

kubelet/CRI implementations could fail on pods using this enhancement and we should be able to detect and monitor that

I did a test on whether the CRI implementation accepts special characters in env var names. The container runtime is more lenient than k8s in accepting special characters in env var names.

ref: https://github.com/HirazawaUi/verfiy-container-env

But I agree that we should do some monitoring of it to avoid unexpected problems.

[HirazawaUi]

Can we update the "Monitoring Requirements" to reflect that we will look into this in Beta and add a note to the graduation criteria?

We should also include (for GA) some "Troubleshooting" details for how to deal with incompatible kubelet/CRI implementations.

so I'd like that range to be sufficiently wide (all supported versions?) before GA.

Okay, I'll add those to the KEP.

[HirazawaUi]

I merged the commit of this PR to #4482