Introduce metrics for pdcsi node

[hajiler]

What type of PR is this?
/kind feature

What this PR does / why we need it:
This PR adds metrics capability for the PDCSI node server. Metrics enable us to define SLO/Alerts for the node server. This PR specifically adds a metric for mount errors.

Which issue(s) this PR fixes:

Fixes #

Special notes for your reviewer:

Does this PR introduce a user-facing change?:

adds metrics for node server including:
- 'process_start_time': start time of the container for use in metric scraping
- 'node_mount_errors': error types which occur during volume mounting

[k8s-ci-robot]

Welcome @hajiler!

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[k8s-ci-robot]

Hi @hajiler. 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.

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[sunnylovestiramisu]

/ok-to-test

[hajiler]

/assign msau

[k8s-ci-robot]

@hajiler: GitHub didn't allow me to assign the following users: msau.

Note that only kubernetes-sigs members with read permissions, repo collaborators and people who have commented on this issue/PR can be assigned. Additionally, issues/PRs can only have 10 assignees at the same time.
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In response to this:

/assign msau

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[tyuchn]

/assign msau

[k8s-ci-robot]

@tyuchn: GitHub didn't allow me to assign the following users: msau.

Note that only kubernetes-sigs members with read permissions, repo collaborators and people who have commented on this issue/PR can be assigned. Additionally, issues/PRs can only have 10 assignees at the same time.
For more information please see the contributor guide

In response to this:

/assign msau

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.

[sunnylovestiramisu]

/assign @msau42

[hajiler]

/retest

[sunnylovestiramisu]

Has this change been end to end tested? For example on a GCE cluster, you can intentionally return an error at the mount step to trigger the emission.

[hajiler]

Has this change been end to end tested? For example on a GCE cluster, you can intentionally return an error at the mount step to trigger the emission.

Yes, the metrics have successfully been emmitted and are visible on monarch: https://screenshot.googleplex.com/8QfU5iD7cBL8mAS

[sunnylovestiramisu]

For other reviewers if you want them to take a look as well
/hold

[sunnylovestiramisu]

/lgtm
/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

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

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Needs approval from an approver in each of these files:

• OWNERS [sunnylovestiramisu]

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[sunnylovestiramisu]

/lgtm

[k8s-ci-robot]

@hajiler: 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-2022	9e68dea	link	false	/test pull-gcp-compute-persistent-disk-csi-driver-e2e-windows-2022

Full PR test history. Your PR dashboard. Please help us cut down on flakes by linking to an open issue when you hit one in your PR.

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. I understand the commands that are listed here.

[hajiler]

/retest-required

[hajiler]

/remove-hold