metrics

prometheus

prometheus enables Prometheus metrics for CoreDNS.

The default location for the metrics is localhost:9153. The metrics path is fixed to /metrics. The following metrics are exported:

• coredns_dns_request_count_total{zone, proto, family}
• coredns_dns_request_duration_milliseconds{zone}
• coredns_dns_request_size_bytes{zone, proto}
• coredns_dns_request_do_count_total{zone}
• coredns_dns_request_type_count_total{zone, type}
• coredns_dns_response_size_bytes{zone, proto}
• coredns_dns_response_rcode_count_total{zone, rcode}

Each counter has a label zone which is the zonename used for the request/response.

Extra labels used are:

• proto which holds the transport of the response ("udp" or "tcp")
• The address family (family) of the transport (1 = IP (IP version 4), 2 = IP6 (IP version 6)).
• type which holds the query type. It holds most common types (A, AAAA, MX, SOA, CNAME, PTR, TXT, NS, SRV, DS, DNSKEY, RRSIG, NSEC, NSEC3, IXFR, AXFR and ANY) and "other" which lumps together all other types.
• The response_rcode_count_total has an extra label rcode which holds the rcode of the response.

If monitoring is enabled, queries that do not enter the plugin chain are exported under the fake name "dropped" (without a closing dot - this is never a valid domain name).

Syntax

prometheus [ADDRESS]

For each zone that you want to see metrics for.

It optionally takes an address to which the metrics are exported; the default is localhost:9153. The metrics path is fixed to /metrics.

Examples

Use an alternative address:

. {
    prometheus localhost:9253
}

Bugs

When reloading, we keep the handler running, meaning that any changes to the handler's address aren't picked up. You'll need to restart CoreDNS for that to happen.