Check for explicit label or metadata to include a pod in accounting

[rptaylor]

Currently all pods in a selected namespace are accounted.

If we can use a prometheus query that will e.g. only count pods with a certain label or annotation it would be a more explicit opt-in. Or maybe (possibly less preferable) only account pods with a given name prefix (e.g. atlas-harvester-*).

[rptaylor]

Here are pod metrics:
https://github.com/kubernetes/kube-state-metrics/blob/main/docs/metrics/workload/pod-metrics.md

There is a completely different metric kube_pod_labels but only if --metric-labels-allowlist is configured. Also there would need to be some joining statement.

It might be better to set a scrapeconfig rule in Prometheus to ensure that Prometheus only contains the metrics of pods that you want to account.