[receiver/kubeletstats] Add k8s.node.rlimit metrics to track max pid and current count

[jinja2]

Component(s)

receiver/kubeletstats

Is your feature request related to a problem? Please describe.

One of the eviction signals used by kubelet is pid.available (available process identifiers). I'd like to be able to track pid utilization on a host.

Describe the solution you'd like

The /stats/summary api exposes 2 useful metrics to track pids available on a node, node.rlimit.curproc and node.rlimit.maxpid. We should optionally scrape these 2 additional metrics from stats/summary endpoint to allow for tracking of pid utilization.

Describe alternatives you've considered

We could technically get the running processes from the processes scraper of hostmetrics receiver but I did not find metrics for getting the limit which is set to min("/proc/sys/kernel/pid_max", "/proc/sys/kernel/threads-max"). We might consider adding pid_max and threads-max to hostmetrics/processes receiver since these are useful limits to track in general whether running k8s or not.

Additional context

No response

[github-actions]

Pinging code owners:

• receiver/kubeletstats: @dmitryax @TylerHelmuth

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[TylerHelmuth]

Seems like a good set of optional metrics. Since it is related to /stats/summary I like doing it in the kubeletstatsreceiver.

[github-actions]

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Pinging code owners:

• receiver/kubeletstats: @dmitryax @TylerHelmuth

See Adding Labels via Comments if you do not have permissions to add labels yourself.

[github-actions]

This issue has been closed as inactive because it has been stale for 120 days with no activity.