Monitoring Caddy with Prometheus metrics — Caddy Documentation
https://caddyserver.com/docs/metrics
Like any process monitored with Prometheus, Caddy exposes an HTTP endpoint that responds in the Prometheus exposition format. Caddy's Prometheus client is also configured to respond with the OpenMetrics exposition format if negotiated (that is, if the Accept header is set to application/openmetrics-text; version=0.0.1).