David.benque/prevent empty resource propagation upstream 2

[dbenque]

Which component this PR applies to?

vertical-pod-autoscaler/admission-controller

What type of PR is this?

/kind bug

What this PR does / why we need it:

Using external recommender that was coming with a bug, we ended up with a VPA object that was presenting a recommendation for a resource that has an empty name:

 resources:
          limits:
            cpu: "1"
            memory: 3Gi
          requests:
            "": "0"              <== empty key
            cpu: "1"
            ephemeral-storage: 10Gi
            memory: 3Gi

In this PR we are proposing to sanitise the recommendation by removing any resource key that would be empty so that the admission is not pushing "garbage" to the pods.

Possible extension: instead of purging empty key, we could have a list of allowed resourceName given as input parameter of the admission. This would also allow us to purge unknown resource or the one coming with typo.

Which issue(s) this PR fixes:

Special notes for your reviewer:

Does this PR introduce a user-facing change?

If a recommendation comes with a resource key that is empty, this resource will be ignored in the admission-controller.

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

[dbenque]

@jbartosik,
This is the same PR than #5900, that I am closing because I did some bad rebase activities in my tree.
This PR contains the initial commit, your contribution in previous PR, and the changes relative to your code review.

Sorry for moving this here (new PR), but I preferred to restart from a clean codebase.

[mwielgus]

/lgtm
/approve

[mwielgus]

/lgtm
/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: dbenque, mwielgus

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• vertical-pod-autoscaler/OWNERS [mwielgus]

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