feat(CustomResourceState): Support quantities and percentages

[mrueg]

What this PR does / why we need it:
In order to be able to deprecate the VPA completely, CRS needs to be aware of quantities. See #1790 (comment)

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):
See also #1790

[logicalhan]

/triage accepted
/assign @rexagod

[logicalhan]

/triage accepted
/assign @rexagod

[rexagod]

@mrueg Can we incorporate support for percentages as well? IIRC that's the only other quantity format that's causing issues.

[mrueg]

@rexagod good idea, I've added support for it as well.

[rexagod]

I see this incorporates support for path pointing to such quantities, but it seems valueFrom still needs to inherit this behavior. We can do that in a different PR, or get it addressed in this one itself, whichever sounds better. 👍🏼

            # Works.
            type: Gauge
            gauge:
              path: [foo, bar, baz, que]

            # Needs to be addressed.
            type: Gauge
            gauge:
              path: [foo]
              valueFrom: [bar, baz, que]

[mrueg]

@rexagod I've added a valueFrom testcase, this seems to work for both. Can you clarify if I am missing anything?

[rexagod]

Ah, yep, that was my bad. The PR is good for valueFrom. I forgot the issue with multiple relative-path in valueFrom still persists. Basically, I was testing this PR on this config,

            # Same as in the example above.
            type: Gauge
            gauge:
              path: [foo]
              valueFrom: [bar, baz, que]

when I should've tested it on,

            # Works.
            type: Gauge
            gauge:
              path: [foo, bar, baz]
              valueFrom: [que] # Only single-paths are supported as of now.

---

We just need to resolve the failing test and this should be good! 🚀

[mrueg]

@rexagod I rebased on the latest main branch and fixed the test. :)

[rexagod]

/lgtm
Thank you for the patch! :)

[k8s-ci-robot]

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[djfinnoy]

Any chance of getting this included in a release soon? We need it :)