Add a metric that reports the VMI last connection timestamp

[assafad]

What this PR does

Add kubevirt_vmi_last_api_connection_timestamp_seconds metric, which reports the last connection timestamp per VMI. Connections covered: console, vnc, usbredir, portforward and SSH.

Fixes https://issues.redhat.com/browse/CNV-14659

Why we need it and why it was done in this way

This metric will help users to identify VMs that have not been logged into for a long time and have allocated resources but are not actually being used.

Checklist

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• Design: A design document was considered and is present (link) or not required
• PR: The PR description is expressive enough and will help future contributors
• Code: Write code that humans can understand and Keep it simple
• Refactor: You have left the code cleaner than you found it (Boy Scout Rule)
• Upgrade: Impact of this change on upgrade flows was considered and addressed if required
• Testing: New code requires new unit tests. New features and bug fixes require at least on e2e test
• Documentation: A user-guide update was considered and is present (link) or not required. You want a user-guide update if it's a user facing feature / API change.
• Community: Announcement to kubevirt-dev was considered

Release note

Add kubevirt_vmi_last_connection_timestamp_seconds metric

[kubevirt-bot]

Skipping CI for Draft Pull Request.
If you want CI signal for your change, please convert it to an actual PR.
You can still manually trigger a test run with /test all

[assafad]

/test pull-kubevirt-e2e-k8s-1.29-sig-monitoring

[victortoso]

/cc

[0xFelix]

I think that might be a little misleading. What about connections to VNC/SSH/RDP via a service or secondary interface? As it stands, this would indicate an unused VMI, although it could be accessed via the aforementioned.

[assafad]

Updated. Please see https://github.com/kubevirt/kubevirt/pull/11934/files#r1618522817.

[sradco]

/lgtm

[0xFelix]

/lgtm

Thanks

[enp0s3]

/approve
@assafad Thank you!

[kubevirt-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: enp0s3

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[sradco]

/lgtm

[kubevirt-commenter-bot]

Required labels detected, running phase 2 presubmits:
/test pull-kubevirt-e2e-windows2016
/test pull-kubevirt-e2e-kind-sriov
/test pull-kubevirt-e2e-k8s-1.30-ipv6-sig-network
/test pull-kubevirt-e2e-k8s-1.28-sig-network
/test pull-kubevirt-e2e-k8s-1.28-sig-storage
/test pull-kubevirt-e2e-k8s-1.28-sig-compute
/test pull-kubevirt-e2e-k8s-1.28-sig-operator
/test pull-kubevirt-e2e-k8s-1.29-sig-network
/test pull-kubevirt-e2e-k8s-1.29-sig-storage
/test pull-kubevirt-e2e-k8s-1.29-sig-compute
/test pull-kubevirt-e2e-k8s-1.29-sig-operator

[kubevirt-commenter-bot]

/retest-required
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Silence the bot with an /lgtm cancel or /hold comment for consistent failures.

[kubevirt-commenter-bot]

/retest-required
This bot automatically retries required jobs that failed/flaked on approved PRs.
Silence the bot with an /lgtm cancel or /hold comment for consistent failures.

[kubevirt-bot]

@assafad: 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-kubevirt-check-tests-for-flakes	d21cdd9	link	false	/test pull-kubevirt-check-tests-for-flakes

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