Metrics

This module enables prometheus metrics for Caddy.

Use

In your Caddyfile:

prometheus

For each virtual host that you want to see metrics for.

It optionally takes an address where the metrics are exported, the default is localhost:9180. The metrics path is fixed to /metrics.

With caddyext you'll need to put this module early in the chain, so that the duration histogram actually makes sense. I've put it at number 0.

Metrics

The following metrics are exported:

• caddy_http_request_count_total{host, family, proto}
• caddy_http_request_duration_seconds{host, family, proto}
• caddy_http_response_size_bytes{host}
• caddy_http_response_status_count_total{host, status}

Each counter has a label host which is the hostname used for the request/response.

The status_count metrics has an extra label status which holds the status code.

The request_count_total and request_duration_seconds also has the protocol family in the family label, this is either 1 (IP version 4) or 2 (IP version 6) and the HTTP protocol major and minor version (in the proto label) used: 1.x or 2 signifying HTTP/1.x or HTTP/2.