feat(hpa): status current metric

[tanguyfalconnet]

Signed-off-by: Tanguy Falconnet tfalconnet.externe@bedrockstreaming.com

What this PR does / why we need it:

We want to be able to have current status of target metrics used by HPA.
We are currently not able to know if our HPA target metrics are healthy or in <unknown> state. Used in pair with prometheus-adapter for custom metric scaling, this is an important metric to check to monitor our clusters.

How does this change affect the cardinality of KSM: (increases, decreases or does not change cardinality)

Increases, as it adds a new metric kube_horizontalpodautoscaler_status_current_target_metric, mostly the same as kube_horizontalpodautoscaler_spec_target_metric

Which issue(s) this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged):
Fixes #

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: tanguyfalconnet / name: Tanguy Falconnet (3eb7aa4, 6906e07, b26d663, 20084df, b09674c, 8e5d283)

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[fpetkovski]

This is looking good so far, just a few nits from my side

[fpetkovski]

Thanks for the contribution. Could you you also sign the CLA so that we can make the CI green?

You can squash all your commits and run

git commit --amend --no-edit --signoff

[tanguyfalconnet]

Thanks for the contribution. Could you you also sign the CLA so that we can make the CI green?

You can squash all your commits and run

git commit --amend --no-edit --signoff

CLA is being reviewed by my company. I'll sign it when everything is ready on our side. Next time it'll go faster ^^

[mrueg]

@tanguyfalconnet do you have an update from your company on the CLA?

[tanguyfalconnet]

@mrueg It's finally ok. It seems that similar code is already merged. I'll let you close it/merge it as you wish.

[mrueg]

Thanks for the update @tanguyfalconnet!
We're waiting on a response from the author of #1788 (comment) to make sure that it's clear where this code is coming from. So I'll keep this open so we can still use it to ensure correct authorship.

[mrueg]

/lgtm

/hold
for @fpetkovski @dgrisonnet to take a look.

[dgrisonnet]

Thank you for looking into this @tanguyfalconnet.

/lgtm
/approve
/unhold

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: dgrisonnet, mrueg, tanguyfalconnet

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