A restart Never static pod does not recreate mirror pod when it is deleted

[smarterclayton]

What happened?

We have never fully clarified the behavior of restart=Never mirror pods, but they currently behave in surprising ways. At minimum, the following questions should be answered and documented:

1. Should the mirror pod be recreated if the kubelet detects it is missing?
2. Should a terminal mirror pod block re-execution of a restart=Never static pod on kubelet restart?

/sig node

What did you expect to happen?

Uncertain

How can we reproduce it (as minimally and precisely as possible)?

1. Create a restartPolicy=Never static pod
2. wait for it to reach completion via mirror pod
3. Delete the mirror pod
4. Restart kubelet

Anything else we need to know?

No response

Kubernetes version

$ kubectl version
# paste output here

Cloud provider

OS version

# On Linux:
$ cat /etc/os-release
# paste output here
$ uname -a
# paste output here

# On Windows:
C:\> wmic os get Caption, Version, BuildNumber, OSArchitecture
# paste output here

Install tools

Container runtime (CRI) and version (if applicable)

Related plugins (CNI, CSI, ...) and versions (if applicable)

[aojea]

/sig node

static pods will benefit of a nice doc with an state machine diagram 😉

[smarterclayton]

I've got a state diagram deck incoming to complement these bugs

[sftim]

I've got a state diagram deck incoming to complement these bugs

Mermaid versions welcome, especially for the K8s docs

[SergeyKanzhelev]

/kind documentation

[SergeyKanzhelev]

/triage accepted

[k8s-triage-robot]

This issue has not been updated in over 1 year, and should be re-triaged.

You can:

• Confirm that this issue is still relevant with /triage accepted (org members only)
• Close this issue with /close

For more details on the triage process, see https://www.kubernetes.dev/docs/guide/issue-triage/

/remove-triage accepted