Expose procfs metrics

[mattmoor]

/area monitoring /area networking /kind feature /kind good-first-issue

Expected Behavior

I'd like to see us exporting a number of system stats available from /proc/... via opencensus. This includes, but isn't limited to the /proc/net/sockstat info we started dumping when our http reverse proxying fails (to try to determine socket exhaustion).

Actual Behavior

We don't.

Additional Info

I'd recommend we use something like github.com/prometheus/procfs to reach /proc in a structured way, however, it currently lacks /proc/net/sockstat. It does however have at least one sibling of sockstat, with good documentation for how to chase down the format of these files for parsing.

I'd recommend that we implement sockstat support in procfs upstream and then use it (and what's already available) to expose a number of system metrics periodically.

cc @Harwayne @tcnghia @mdemirhan @dprotaso

[github-actions[bot]]

This issue is stale because it has been open for 90 days with no activity. It will automatically close after 30 more days of inactivity. Reopen the issue with /reopen. Mark the issue as fresh by adding the comment /remove-lifecycle stale.

[mattmoor]

/lifecycle frozen