Disable matching on few selectors. Remove duplicates.

[Ramyak]

What type of PR is this?

/kind bug

What this PR does / why we need it:
Problem: When there are 2 selectors(eg: service and replication controller), it is sufficient to match any one selector for distribution. This creates imbalance [selector match code].

Pods from previous deploys matches service selector and are counted when distributing pods across zones/nodes (Even though they do not match replicaset selector) . These pods will be deleted. After the deploy completes, the cluster is imbalanced - by zone and/or pods per node.

Fix: All selectors must match pods. Partial matches are still allowed.

Which issue(s) this PR fixes:
Fixes #71327

Special notes for your reviewer:
#71328
Splitting this into 2 reviews.

Does this PR introduce a user-facing change?:

Fix SelectorSpreadPriority scheduler to match all selectors when distributing pods.

/sig scheduling

[k8s-ci-robot]

Hi @Ramyak. Thanks for your PR.

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[wgliang]

/ok-to-test

[Ramyak]

/test pull-kubernetes-e2e-gce-100-performance
/test pull-kubernetes-integration
/test pull-kubernetes-kubemark-e2e-gce-big

[Ramyak]

/assign @k82cn
/assign @bsalamat

[bsalamat]

Thanks, @Ramyak for the fix. Could you please address my comment?

[bsalamat]

This PR addresses "Problem 2" of #71327, but it is a diversion from the existing behavior. Our existing code gets a union of all pods that match any of the selectors. This PR changes the union to an intersection operator. While I don't have a particular scenario in mind that would break if someone uses a standard collection, it is easy to find scenarios where pods with custom labels will no longer spread properly after this change. For that reason, I would like to think a bit more about this PR before I can approve it.

[bsalamat]

/approve

I thought more about this change and given that the pattern mentioned in the issue can happen for many users, I decided to approve it.

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: bsalamat, Ramyak

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• pkg/scheduler/OWNERS [bsalamat]

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[bsalamat]

/lgtm

[Ramyak]

/test pull-kubernetes-e2e-gce-100-performance
/test pull-kubernetes-integration