[prometheus-smartctl-exporter] Allow PodMonitor and PriorityClass configuration

[briend]

What this PR does / why we need it

Which issue this PR fixes

• Allows use of PodMonitor instead of the traditional ServiceMonitor. This can be more efficient than creating a Service (unnecessary iptables rules overhead) and avoid ServiceMonitor Endpoint issues with >1000 Pods:
  • Add ServiceDiscoveryRole configuration to toggle service discovery via EndpointSlice vs Endpoints prometheus-operator/prometheus-operator#6672
  • PodMonitor vs ServiceMonitor what is the difference? prometheus-operator/prometheus-operator#3119
• Allows setting a priorityClassName
• If ServiceMonitor is not enabled, the Service is not created either

Special notes for your reviewer

Checklist

• DCO signed
• Chart Version bumped
• Title of the PR starts with chart name (e.g. [prometheus-couchdb-exporter])

[kfox1111]

Maybe make this service.enabled... There could be folks using the service along with a manually installed service monitor or prometheus config.

The rest looks good though. Thanks! :)

[briend]

Thanks @kfox1111 , I agree. I've added that and leave Service enabled by default just in case.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Any further update will cause the issue/pull request to no longer be considered stale. Thank you for your contributions.