Add feature flag treat-pod-as-always-schedulable

[SaschaSchwarze0]

Same as #15397 I had missed that that one was auto-closed.

The feature flag allows to declare that Pods in the system will eventually all get scheduled and Revisions should therefore not be marked unschedulable

Fixes #14862

Proposed Changes

Unfortunately, I never got feedback in above issue, so trying with a PR now:

• New feature treat-pod-as-always-schedulable is added with default Disabled.
• If enabled, the revision reconciler will skip the check whether a pod is not scheduled and therefore never mark a revision as unschedulable.

EDIT: there was some feedback in the issue in the meantime and it has since then also been auto-closed. @dprotaso @skonto you were involved in a few discussions there, but without real outcome. Appreciate clear feedback whether we can take this forward or not.

Release Note

You can now set the new feature `treat-pod-as-always-schedulable` to enabled in the config-defaults ConfigMap. As a result, Knative will not mark revisions as Unschedulable when a Pod is not scheduled. This makes sense if you want to omit this transient state in clusters that have cluster-autoscaling set up, and you can guarantee that all Pods will be eventually scheduled.

[knative-prow[bot]]

Hi @SaschaSchwarze0. Thanks for your PR.

I'm waiting for a github.com 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.

[knative-prow[bot]]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: SaschaSchwarze0 Once this PR has been reviewed and has the lgtm label, please assign dprotaso 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:

• OWNERS
• pkg/apis/OWNERS

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

[codecov[bot]]

Codecov Report

:white_check_mark: All modified and coverable lines are covered by tests. :white_check_mark: Project coverage is 80.07%. Comparing base (2428689) to head (fa8dbd5). :warning: Report is 45 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #16146      +/-   ##
==========================================
- Coverage   80.09%   80.07%   -0.02%     
==========================================
  Files         214      214              
  Lines       16932    16936       +4     
==========================================
+ Hits        13561    13562       +1     
- Misses       3014     3017       +3     
  Partials      357      357              

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.

:rocket: New features to boost your workflow:

• :snowflake: Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[knative-prow-robot]

PR needs rebase.

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.