Update RAID logic and post-RAID validation to integrate Datacache support for GKE nodes

[hungnguyen243]

What type of PR is this?

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/kind api-change
/kind bug
/kind cleanup
/kind design
/kind documentation
/kind failing-test

/kind feature

/kind flake

What this PR does / why we need it:
Update RAIDing logic to fetch requested local SSD count for Datacache from GKE node label, set up RAIDing for Datacache with the corresponding local SSD number, and validate RAID-ing config afterwards.
Which issue(s) this PR fixes:

Fixes #

Special notes for your reviewer:

Does this PR introduce a user-facing change?:

Update RAID logic and post-RAID validation to integrate Data Cache support for GKE nodes

[k8s-ci-robot]

Hi @hungnguyen243. Thanks for your PR.

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[Sneha-at]

/ok-to-test

[hungnguyen243]

/retest

[hungnguyen243]

/retest

[hungnguyen243]

/retest-required

[sunnylovestiramisu]

Please update release note in the PR description to:

Update RAID logic and post-RAID validation to integrate Data Cache support for GKE nodes

The script we use to create a change log for the release is reading these release notes to automatically generate the change list.

[Sneha-at]

@sunnylovestiramisu do you think we can add any regex for any other check here to ensure we always pick up the path.
Command output:

$ sudo mdadm --detail --scan
ARRAY /dev/md/kubelet_ephemeral_storage metadata=1.2 name=kubelet_ephemeral_storage UUID=xxxx
ARRAY /dev/md126 metadata=1.2 name=csi-driver-data-cache UUID=xxxx

[sunnylovestiramisu]

Since we are greping the "raidedLocalSsdName" will always get 1 array(hopefully):
ARRAY /dev/md126 metadata=1.2 name=csi-driver-data-cache UUID=xxxx

The path itself should be in some format /dev/md* ?

[hungnguyen243]

I think if the grep 'csi-driver-data-cache' is able to fetch the line, the path should be correct since how else is a RAID array created with the same name but at some random path? A possible error is when the RAID fails and so the grep will not return anything, which is caught before we process the infoString.

[Sneha-at]

It might as well be /dev/csi-driver-data-cache for our E2E tests and in certain scenarios :( like if ephemeral storage is not used. @hungnguyen243 to confirm

[hungnguyen243]

For our E2E tests, it will be /dev/md/csi-driver-datacache (I double checked on this), so adding a regex check should be fine, but as I mentioned above, it shouldn't be necessary?

[sunnylovestiramisu]

I am not a fan of regex check without test coverage anyway, and for this one it seems not necessary to add really.

[sunnylovestiramisu]

Review for data cache

[sunnylovestiramisu]

Since we are greping the "raidedLocalSsdName" will always get 1 array(hopefully):
ARRAY /dev/md126 metadata=1.2 name=csi-driver-data-cache UUID=xxxx

The path itself should be in some format /dev/md* ?

[sunnylovestiramisu]

/lgtm
/approve

We need @mattcary to force merge because the windows test is not fixed yet.

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: hungnguyen243, sunnylovestiramisu

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[k8s-ci-robot]

@hungnguyen243: The following test failed, say /retest to rerun all failed tests or /retest-required to rerun all mandatory failed tests:

Test name	Commit	Details	Required	Rerun command
pull-gcp-compute-persistent-disk-csi-driver-e2e-windows-2019	e33bb0d	link	false	/test pull-gcp-compute-persistent-disk-csi-driver-e2e-windows-2019

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[hungnguyen243]

/retest-required