customresourcestate: Use pluralize logic from k8s/apimachinery

[mrueg]

What this PR does / why we need it:

kubernetes and kubebuilder use a different logic to generate / guess plurals. The goal of this PR is to use the same logic as Kubernetes.

Kubernetes: https://github.com/kubernetes/apimachinery/blob/master/pkg/api/meta/restmapper.go#L126
Kubebuilder: https://github.com/gobuffalo/flect

See also:
kubernetes-sigs/kubebuilder#3402
kubernetes-sigs/kubebuilder#3408

How does this change affect the cardinality of KSM: (increases, decreases or does not change cardinality)
None
Which issue(s) this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged):
None

[k8s-ci-robot]

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[logicalhan]

But the pluralization logic in upstream k8s is super broken...

[logicalhan]

What does this solve?

Kubebuilder didn't opt to use upstream k8s pluralization logic because it was so wonky to begin with, so arguably this makes things worse.

[logicalhan]

For instance, PodSchedulingHints gets pluralized to PodSchedulingHintses using upstream k8s pluralization logic. And to fix the utterly broken pluralization logic, we have manual overrides all over the place: https://github.com/kubernetes/kubernetes/blob/7a4c4eaae7a7295d5969734446bc4077d9fe848f/staging/src/k8s.io/code-generator/cmd/client-gen/args/args.go#L69

[mrueg]

@logicalhan I am aware that it's broken. At least it's somewhat deterministically broken instead of relying on flect to have a better heuristic (and also sometimes getting things wrong #2051).

What are better options?
Should we query the Kubernetes API during startup instead?

[k8s-ci-robot]

PR needs rebase.

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[a-hilaly]

@mrueg how about using https://github.com/gertd/go-pluralize? overall we've observed some pluralize issues with kubebuilder/flect and almost never with go-pluralize

[rexagod]

That's doable, but there will always be a room for risk unless machinery and kubebuilder decide on the same pluralizing logic, which ideally should become the de-facto standard for generating resource names.

[dgrisonnet]

Should we query the Kubernetes API during startup instead?

That sound like the best way to avoid bugs caused by differences in naming.
We should already have a discovery logic in the custom state metrics code to allow simplification via regex, so we could get the list of existing resources there.

[dgrisonnet]

/triage accepted

[mrueg]

@dgrisonnet #2093 I think moving to GRV might make this obsolete

[dgrisonnet]

Oh right, I need to catch up on that. Thanks for the update

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/close

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@k8s-triage-robot: Closed this PR.

In response to this:

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/close

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