4116a4ebdb
Signed-off-by: Ondřej Benkovský <ondrej.benkovsky@jamf.com> Signed-off-by: Ondřej Benkovský <ondrej.benkovsky@jamf.com>
90 lines
3.9 KiB
Markdown
90 lines
3.9 KiB
Markdown
# prometheus
|
|
|
|
## Name
|
|
|
|
*prometheus* - enables [Prometheus](https://prometheus.io/) metrics.
|
|
|
|
## Description
|
|
|
|
With *prometheus* you export metrics from CoreDNS and any plugin that has them.
|
|
The default location for the metrics is `localhost:9153`. The metrics path is fixed to `/metrics`.
|
|
|
|
In addition to the default Go metrics exported by the [Prometheus Go client](https://prometheus.io/docs/guides/go-application/),
|
|
the following metrics are exported:
|
|
|
|
* `coredns_build_info{version, revision, goversion}` - info about CoreDNS itself.
|
|
* `coredns_panics_total{}` - total number of panics.
|
|
* `coredns_dns_requests_total{server, zone, view, proto, family, type}` - total query count.
|
|
* `coredns_dns_request_duration_seconds{server, zone, view, type}` - duration to process each query.
|
|
* `coredns_dns_request_size_bytes{server, zone, view, proto}` - size of the request in bytes.
|
|
* `coredns_dns_do_requests_total{server, view, zone}` - queries that have the DO bit set
|
|
* `coredns_dns_response_size_bytes{server, zone, view, proto}` - response size in bytes.
|
|
* `coredns_dns_responses_total{server, zone, view, rcode, plugin}` - response per zone, rcode and plugin.
|
|
* `coredns_dns_https_responses_total{server, status}` - responses per server and http status code.
|
|
* `coredns_plugin_enabled{server, zone, view, name}` - indicates whether a plugin is enabled on per server, zone and view basis.
|
|
|
|
Almost each counter has a label `zone` which is the zonename used for the request/response.
|
|
|
|
Extra labels used are:
|
|
|
|
* `server` is identifying the server responsible for the request. This is a string formatted
|
|
as the server's listening address: `<scheme>://[<bind>]:<port>`. I.e. for a "normal" DNS server
|
|
this is `dns://:53`. If you are using the *bind* plugin an IP address is included, e.g.: `dns://127.0.0.53:53`.
|
|
* `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, HTTPS, IXFR, AXFR and ANY) and "other" which lumps together all
|
|
other types.
|
|
* `status` which holds the https status code. Possible values are:
|
|
* 200 - request is processed,
|
|
* 404 - request has been rejected on validation,
|
|
* 400 - request to dns message conversion failed,
|
|
* 500 - processing ended up with no response.
|
|
* the `plugin` label holds the name of the plugin that made the write to the client. If the server
|
|
did the write (on error for instance), the value is empty.
|
|
|
|
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).
|
|
|
|
Other plugins may export additional stats when the _prometheus_ plugin is enabled. Those stats are documented in each
|
|
plugin's README.
|
|
|
|
This plugin can only be used once per Server Block.
|
|
|
|
## Syntax
|
|
|
|
~~~
|
|
prometheus [ADDRESS]
|
|
~~~
|
|
|
|
For each zone that you want to see metrics for.
|
|
|
|
It optionally takes a bind address to which the metrics are exported; the default
|
|
listens on `localhost:9153`. The metrics path is fixed to `/metrics`.
|
|
|
|
## Examples
|
|
|
|
Use an alternative listening address:
|
|
|
|
~~~ corefile
|
|
. {
|
|
prometheus localhost:9253
|
|
}
|
|
~~~
|
|
|
|
Or via an environment variable (this is supported throughout the Corefile): `export PORT=9253`, and
|
|
then:
|
|
|
|
~~~ corefile
|
|
. {
|
|
prometheus localhost:{$PORT}
|
|
}
|
|
~~~
|
|
|
|
## Bugs
|
|
|
|
When reloading, the Prometheus handler is stopped before the new server instance is started.
|
|
If that new server fails to start, then the initial server instance is still available and DNS queries still served,
|
|
but Prometheus handler stays down.
|
|
Prometheus will not reply HTTP request until a successful reload or a complete restart of CoreDNS.
|
|
Only the plugins that register as Handler are visible in `coredns_plugin_enabled{server, zone, name}`. As of today the plugins reload and bind will not be reported.
|