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]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: flavono123
Once this PR has been reviewed and has the lgtm label, please assign mwielgus for approval. For more information see the Code Review Process.

The full list of commands accepted by this bot can be found here.

Needs approval from an approver in each of these files:

• OWNERS

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[k8s-ci-robot]

Hi @flavono123. Thanks for your PR.

I'm waiting for a kubernetes-sigs member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

I understand the commands that are listed here.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.

[coveralls]

Pull Request Test Coverage Report for Build 15268621110

Details

• 29 of 29 (100.0%) changed or added relevant lines in 2 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.07%) to 82.062%

---

Totals
Change from base Build 15202551561:	0.07%
Covered Lines:	10211
Relevant Lines:	12443

---

💛 - 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?

[flavono123]

rebased

counting drifted nodeclaims in (*Cluster).updateNodePoolResources since (*Controller) resourceCountsFor has removed in #2110

i didnt add testcases for "state", updateNodePoolResources i mean, so just let me know if they are required