Feat: improve VPA filtering and checkpoint garbage collection

[omerap12]

What type of PR is this?

/kind feature

What this PR does / why we need it:

Currently, the recommender's garbage collection for checkpoints iterates through all namespaces in the cluster, ignoring the vpaObjectNamespace and ignoredNamespaces flags. In large-scale clusters, this can lead to performance issues. This PR addresses the problem by ensuring that the garbage collection logic respects the specified flags.

Which issue(s) this PR fixes:

Fixes #7697

Special notes for your reviewer:

Does this PR introduce a user-facing change?

Fixes VPA recommender garbage collection to respect `vpaObjectNamespace` and `ignoredNamespaces` flags, improving performance in large-scale clusters by limiting the scope of namespace checks.

Additional documentation e.g., KEPs (Kubernetes Enhancement Proposals), usage docs, etc.:

Not sure where should I document this change

[k8s-ci-robot]

@omerap12: The label(s) kind/featrue cannot be applied, because the repository doesn't have them.

In response to this:

What type of PR is this?

/kind featrue

What this PR does / why we need it:

Currently, the recommender's garbage collection for checkpoints iterates through all namespaces in the cluster, ignoring the vpaObjectNamespace and ignoredNamespaces flags. In large-scale clusters, this can lead to performance issues. This PR addresses the problem by ensuring that the garbage collection logic respects the specified flags.

Which issue(s) this PR fixes:

Fixes #7697

Special notes for your reviewer:

Does this PR introduce a user-facing change?

Fixes VPA recommender garbage collection to respect `vpaObjectNamespace` and `ignoredNamespaces` flags, improving performance in large-scale clusters by limiting the scope of namespace checks.

Additional documentation e.g., KEPs (Kubernetes Enhancement Proposals), usage docs, etc.:

Not sure where should I document this change

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[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: omerap12
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[omerap12]

/kind feature

[adrianmoisey]

Not sure where should I document this change

I'm not sure if this is a good idea, but what about updating the flags:

autoscaler/vertical-pod-autoscaler/common/flags.go

Lines 45 to 46 in b8719d3

	flag.StringVar(&cf.VpaObjectNamespace, "vpa-object-namespace", apiv1.NamespaceAll, "Namespace to search for VPA objects. Empty means all namespaces will be used.")
	flag.StringVar(&cf.IgnoredVpaObjectNamespaces, "ignored-vpa-object-namespaces", "", "Comma separated list of namespaces to ignore when searching for VPA objects. Empty means no namespaces will be ignored.")

?

[omerap12]

Not sure where should I document this change

I'm not sure if this is a good idea, but what about updating the flags:

autoscaler/vertical-pod-autoscaler/common/flags.go

Lines 45 to 46 in b8719d3

	flag.StringVar(&cf.VpaObjectNamespace, "vpa-object-namespace", apiv1.NamespaceAll, "Namespace to search for VPA objects. Empty means all namespaces will be used.")
	flag.StringVar(&cf.IgnoredVpaObjectNamespaces, "ignored-vpa-object-namespaces", "", "Comma separated list of namespaces to ignore when searching for VPA objects. Empty means no namespaces will be ignored.")

?

sounds good