The Grafana dashboard sample filters on actions_github_com_scale_set_name
and actions_github_com_scale_set_namespace, which are not emitted by ARC.
They are produced by Prometheus relabeling of the listener pod labels.
Document the required scrape configuration, clarify that adding these
labels to listenerMetrics results in empty values, and add a
troubleshooting section for empty panels.
Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
