feat(nodepool): add statuses for nodepool drift

[flavono123]

Fixes #1785

Description

add two statuses of NodePool about drifts:

• Drifted, as one of conditions, indicates if any NodeClaims belonging to the NodePool have drifted
• DriftedNodeClaimCount, as a numeric field, represents the number of NodeClaims that have drifted

print the DriftedNodeClaimCount as a column of result of kubectl get nodepool

How was this change tested?

unit tests are added, make presubmit, kubectl get nodepool -owide on my local k3s

❯ k get nodepool -owide
NAME      NODECLASS   NODES   READY   AGE   WEIGHT   CPU   MEMORY   DRIFTEDNODECLAIMS
default   default                     10m                           

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[k8s-ci-robot]

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[k8s-ci-robot]

Hi @flavono123. Thanks for your PR.

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[coveralls]

Pull Request Test Coverage Report for Build 14198715455

Details

• 21 of 21 (100.0%) changed or added relevant lines in 1 file are covered.
• 5 unchanged lines in 2 files lost coverage.
• Overall coverage increased (+0.02%) to 81.6%

---

Files with Coverage Reduction	New Missed Lines	%
pkg/controllers/disruption/drift.go	2	89.66%
pkg/controllers/provisioning/scheduling/nodeclaim.go	3	88.51%

Totals
Change from base Build 14183583381:	0.02%
Covered Lines:	9677
Relevant Lines:	11859

---

💛 - Coveralls

[rschalo]

Thanks for the contribution! Rather than create a separate controller for tracking this, is it possible to hook into resourceCountsFor for a NodePool in pkg/controllers/nodepool/counter/controller.go? I believe we'd able to count drifted nodes in the c.cluster.ForEachNode(...) call.

[jonathan-innis]

/assign @rschalo

[flavono123]

@rschalo i did, counting drifted nodeclaims, just like for nodes. and added setting the condition of nodepool(not sure the counter controller is the right place though)

[flavono123]

emitting an event is required too?

[k8s-ci-robot]

PR needs rebase.

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