Add support for dnsConfig and dnsPolicy in pod spec

[stevenchen-db]

Fixes #5306

Proposed Changes

• Allow specifying dnsConfig and dnsPolicy in pod specs based (gated behind a feature flag)

Release Note

Allows dnsConfig and dnsPolicy to be specified on pod specs when the feature is enabled in the config-features config map.

[knative-prow]

Hi @stevenchen-db. Thanks for your PR.

I'm waiting for a knative 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.

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[codecov]

Codecov Report

Merging #12897 (af9a7c4) into main (5128270) will decrease coverage by 0.02%.
The diff coverage is 100.00%.

❗ Current head af9a7c4 differs from pull request most recent head 9f4e17a. Consider uploading reports for the commit 9f4e17a to get more accurate results

@@            Coverage Diff             @@
##             main   #12897      +/-   ##
==========================================
- Coverage   87.03%   87.01%   -0.03%     
==========================================
  Files         197      197              
  Lines       14426    14437      +11     
==========================================
+ Hits        12556    12562       +6     
- Misses       1576     1579       +3     
- Partials      294      296       +2     

Impacted Files	Coverage Δ
pkg/apis/config/features.go	95.23% <100.00%> (+0.32%)	⬆️
pkg/apis/serving/fieldmask.go	95.62% <100.00%> (+0.03%)	⬆️
pkg/reconciler/autoscaling/kpa/kpa.go	95.26% <100.00%> (+0.07%)	⬆️
pkg/autoscaler/statserver/server.go	75.55% <0.00%> (-2.23%)	⬇️
pkg/activator/net/revision_backends.go	92.19% <0.00%> (-0.58%)	⬇️

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[psschwei]

/ok-to-test

[nader-ziada]

two quick questions:

• Can we add a test in fieldmask_test.go
• Is there any validation to be added in the k8s_validation.go, for example dnsPolicy allowed values?

[stevenchen-db]

two quick questions:

• Can we add a test in fieldmask_test.go
• Is there any validation to be added in the k8s_validation.go, for example dnsPolicy allowed values?

I plan to manually test that values get passed through and I previously verified that the dnsPolicy and dnsConfig was masked. For this PR, I was primarily going off of several previous PRs that introduced new pod specs such as https://github.com/knative/serving/pull/9072/files and #12715, which appears to not have added field_mask tests maybe since they're all gated behind a feature flag.

I can add validation to dnsPolicy in k8s_validation.go

[dprotaso]

Can we add a test in fieldmask_test.go

Technically the k8s validation test changes covered exercising the field mask code.

Is there any validation to be added in the k8s_validation.go, for example dnsPolicy allowed values?

I would skip this for pod spec fields guarded by feature flags - it's a black box for us and user beware

[dprotaso]

/lgtm
/approve

[knative-prow]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: dprotaso, stevenchen-db

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[stevenchen-db]

Can we add a test in fieldmask_test.go

Technically the k8s validation test changes covered exercising the field mask code.

Is there any validation to be added in the k8s_validation.go, for example dnsPolicy allowed values?

I would skip this for pod spec fields guarded by feature flags - it's a black box for us and user beware

Makes sense, thanks for the clarification!

[psschwei]

Would you also be able to submit a PR to the docs repo to update the feature flag page?

[stevenchen-db]

/retest-required

[dprotaso]

/lgtm

[dprotaso]

/test istio-latest-no-mesh-tls_serving_main