Allow OTel metrics to work with postgres versions greater than 17. If…

[dsessler7]

… postgres_exporter is used with postgres versions greater than 17, create a warning event and set the setup.sql blank.

Checklist:

• Have you added an explanation of what your changes do and why you'd like them to be included?
• Have you updated or added documentation for the change, as applicable?
• Have you tested your changes on all related environments with successful results, as applicable?
  • Have you added automated tests?

Type of Changes:

• New feature
• Bug fix
• Documentation
• Testing enhancement
• Other

What is the current behavior (link to any open issues here)?

Currently, if you are using either metrics exporter (OTel or postgres_exporter) with a postgres version greater than 17, you will get a reconciler error and metrics will not work.

What is the new behavior (if this is a feature change)?

• Breaking change (fix or feature that would cause existing functionality to change)

You can now get metrics with pg > 17 if you use OTel as your exporter. We will not support postgres_exporter with pg versions greater than 17. If you attempt to use postgres_exporter with pg > 17, you will see a warning event and the metrics will essentially be turned off.

Other Information:

[jmckulk]

One naming ⛏️but functionally looks good

[jmckulk]

I think if exporter would make more sense here since we are only talking about exporter specific things (comments, warnings, setup) ⛏️

[dsessler7]

Not sure I follow... In this function the "Exporter" in reconcileExporterSqlSetup refers to both/either OTel and/or postgres_exporter. If the OTel metrics feature is enabled, it takes precedence (even if postgres_exporter is enabled). If OTel metrics isn't enabled, we get the setup for postgres_exporter.

[jmckulk]

That makes sense. I should have said if postgres_exporter... something like this:

if pgmonitor.ExporterEnabled(ctx, cluster) {
  # do some postgres_exporter specific things
  return metrics for postgres_exporter
}

# default to otel
return metrics for otel

It feels weird to me to have

if !otel {
  # do postgres_exporter things
}

[dsessler7]

Well, that's just the thing, if OTel metrics is enabled it will always be used, even if postgres_exporter is also enabled. Also, pgmonitor.ExporterEnabled checks that at least one of OTel metrics or postgres_exporter are enabled (not only postgres_exporter).

I guess I could change it to more of a guard clause for OTel and make postgres_exporter the "default":

if otel {
  return metricsSetupForOTelCollector, nil
}

# do postgres_exporter stuff

But then we're kinda splitting hairs here

[sfc-gh-jmckulka]

Definitely splitting hairs 👍