Add an extra parameter ExitCode to RemoveFailedPods

[yuanchen8911]

The current RemoveFailedPods strategy includes a parameter reason from a terminated container's status (state). In addition to reason, the field exitCode in a container's status, which describes the exit status from the last termination of a container, can provide additional and useful information about a container's termination.

A common use case is AI/ML training jobs often inject/run pre-flight health checks in initContainers and take actions according to the exitCode value when an initContainer fails, e.g., deleting the scheduled job pod via Descheduler.

This PR adds a terminated container's exitCode as an additional parameter to the RemoveFailedPods strategy.

Fix #1380

[yuanchen8911]

/cc @Huang-Wei

[jklaw90]

/ok-to-test

[jklaw90]

@yuanchen8911 could you update the readme

[yuanchen8911]

@yuanchen8911 could you update the readme

Updated README.md.

[yuanchen8911]

@jklaw90, may I have it reviewed? Thanks!

[jklaw90]

/lgtm

Thanks for your pr @yuanchen8911

[yuanchen8911]

/lgtm

Thanks for your pr @yuanchen8911

Would you approve it as well? Thanks!

[ingvagabund]

Worth mentioning the exit codes apply only when the pod's phase is failed.

reasons and exitCodes can be expanded to include reasons of InitContainers as well by setting the optional parameter includingInitContainers to true.

Better to split the sentence into two. "can be expanded to include reasons of InitContainers" applies for reasons only.

[ingvagabund]

You can provide an optional parameter to filter by failed reasons and exitCodes.

You can provide an optional parameter to filter by failed reasons or exitCodes or both.

[yuanchen8911]

Changed the description to

Worth mentioning the exit codes apply only when the pod's phase is failed.

Here's the updated version.
"You can provide optional parameters to filter by failed pods' and containers' reasons. and exitCodes. exitCodes apply to pods' containers with terminated state only."

[yuanchen8911]

Worth mentioning the exit codes apply only when the pod's phase is failed.

reasons and exitCodes can be expanded to include reasons of InitContainers as well by setting the optional parameter includingInitContainers to true.

Better to split the sentence into two. "can be expanded to include reasons of InitContainers" applies for reasons only.

exitCode applies to initContainer too. This is actually the main use cases of the PR. Here's the updated description.

"You can provide optional parameters to filter by failed pods' and containers' reasons. and exitCodes. exitCodes apply to pods' containers with terminated state only."

$ kubectl explain pod.status.initContainerStatuses.state.terminated
KIND:       Pod
VERSION:    v1

FIELD: terminated <ContainerStateTerminated>

DESCRIPTION:
    Details about a terminated container
    ContainerStateTerminated is a terminated state of a container.

FIELDS:
  containerID	<string>
    Container's ID in the format '<type>://<container_id>'

  exitCode	<integer> -required-
    Exit status from the last termination of the container

  finishedAt	<string>
    Time at which the container last terminated

  message	<string>
    Message regarding the last termination of the container

  reason	<string>
    (brief) reason from the last termination of the container

  signal	<integer>
    Signal from the last termination of the container

  startedAt	<string>
    Time at which previous execution of the container started
    ```

[yuanchen8911]

@ingvagabund, thanks for reviewing the PR. I've made the suggested changes to address your comments. Can you take another look please?

[jklaw90]

/lgtm

[a7i]

I believe this would be the first time that we're adding a field to v1alpha2 (but not v1alpha1). I think that's ok, given that it's being deprecated and removed in 1.31.

Just wanted to note that.

[a7i]

/approve as I believe all of @ingvagabund comments were addressed

/lgtm as I believe @jklaw90 already did

Thank you for your contribution @yuanchen8911 and being patient with us

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: a7i

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[a7i]

This will be included as part of v0.30

soon 🤞🏼 ™️

[a7i]

/lgtm

[yuanchen8911]

/approve as I believe all of @ingvagabund comments were addressed

/lgtm as I believe @jklaw90 already did

Thank you for your contribution @yuanchen8911 and being patient with us

Thank you all for reviewing the PR!