Metadata Syncer for vsphere CSI Driver

[RaunakShah]

What this PR does / why we need it:
The goal of Metadata Syncer is to push vSphere container volume metadata (PV labels, PVC labels, the name of the Pod consuming container volume) from Kubernetes Cluster to vSphere.
This metadata will also be presented to VC or Storage Admin on vSphere UI.
For this design we have taken into consideration, that CSI is container orchestrator agnostic, so we cannot directly use Kubernetes objects in the CSI controller/node plugin code. We will be running separate container in the controller plugin pod, to update metadata for CNS Volumes.
We call this container as "Metadata Syncer".

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

Special notes for your reviewer:
Integration, unit and e2e tests for this container will be added in the following PRs. This PR only adds the informer code to perform these updates.

Release note:

Metadata Syncer for vSphere CSI Driver

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[k8s-ci-robot]

Hi @RaunakShah. Thanks for your PR.

I'm waiting for a kubernetes-sigs or kubernetes 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.

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[RaunakShah]

Signed the CLA

[codenrhoden]

/ok-to-test

[RaunakShah]

/assign @codenrhoden
/assign @frapposelli
/assign @dvonthenen
/assign @andrewsykim

[dvonthenen]

Other than the small nit that was pointed out, code-wise this looks pretty good! Awesome job! I can't really comment on whether or not this is doing what is intended... but will rely on others to make that determination.

/lgtm

[codenrhoden]

LGTM

Just the nit from divyen to address and I'm curious about the k/k dependency...

[codenrhoden]

I'll file an issue to follow-up on this later, but this is a really old version of k/k to pull in. It's outside of the "n-2" support policy. The vSphere CPI recently updated it's dependency to 1.15.0, and I know it was a ton of work to do so. At some point the same thing should happen here.

[codenrhoden]

And actually, as I've looked at the new *.go files, the only direct imports of k8s.io/* packages are of klog, client-go, and api. So I'm wondering why kubernetes is being added as a direct dependency here at all... 🤔

[RaunakShah]

Good catch! I had some tests as part of this PR earlier and overlooked removing it when i removed the tests. Since you've pointed it out, maybe we'll look at that internally and try to resolve any issues ASAP. Thanks!

[RaunakShah]

/retest

[RaunakShah]

Thanks @divyenpatel @dvonthenen @codenrhoden for the swift reviews! Ive rebased all commits into one based on your comments

[codenrhoden]

/lgtm
/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: codenrhoden, RaunakShah

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