Metrics

Enable Prometheus metrics with -metrics.

ical-filter-proxy -metrics

Metrics are exposed at /metrics only when metrics are enabled.

Use a management listener to keep metrics separate from public calendar feeds:

ical-filter-proxy -metrics -management-address 127.0.0.1:9090

When -management-address is set, /metrics is served on the management listener. Without it, /metrics is served on the public listener.

Per-calendar metric labels are disabled by default. Enable them with:

ical-filter-proxy -metrics -metrics-calendar-labels

Per-calendar labels are useful for debugging a small known set of calendars, but they increase metric cardinality.

note

Use -management-address with metrics when you want /metrics separated from the public calendar listener.