README ¶
prometheus
Name
prometheus - enables Prometheus 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
.
The following metrics are exported:
coredns_build_info{version, revision, goversion}
- info about CoreDNS itself.coredns_panic_count_total{}
- total number of panics.coredns_dns_request_count_total{server, zone, proto, family}
- total query count.coredns_dns_request_duration_seconds{server, zone}
- duration to process each query.coredns_dns_request_size_bytes{server, zone, proto}
- size of the request in bytes.coredns_dns_request_do_count_total{server, zone}
- queries that have the DO bit setcoredns_dns_request_type_count_total{server, zone, type}
- counter of queries per zone and type.coredns_dns_response_size_bytes{server, zone, proto}
- response size in bytes.coredns_dns_response_rcode_count_total{server, zone, rcode}
- response per zone and rcode.
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 isdns://: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, IXFR, AXFR and ANY) and "other" which lumps together all other types.- The
response_rcode_count_total
has an extra labelrcode
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).
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 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
}
Or via an environment variable (this is supported throughout the Corefile): export PORT=9253
, and
then:
. {
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.
Documentation ¶
Overview ¶
Package metrics implement a handler and plugin that provides Prometheus metrics.
Index ¶
- Variables
- func MustRegister(c *caddy.Controller, cs ...prometheus.Collector)
- func WithServer(ctx context.Context) string
- type Metrics
- func (m *Metrics) AddZone(z string)
- func (m *Metrics) MustRegister(c prometheus.Collector)
- func (m *Metrics) Name() string
- func (m *Metrics) OnFinalShutdown() error
- func (m *Metrics) OnRestart() error
- func (m *Metrics) OnStartup() error
- func (m *Metrics) RemoveZone(z string)
- func (m *Metrics) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error)
- func (m *Metrics) ZoneNames() []string
Constants ¶
This section is empty.
Variables ¶
var ListenAddr string
ListenAddr is assigned the address of the prometheus listener. Its use is mainly in tests where we listen on "localhost:0" and need to retrieve the actual address.
Functions ¶
func MustRegister ¶ added in v1.1.2
func MustRegister(c *caddy.Controller, cs ...prometheus.Collector)
MustRegister registers the prometheus Collectors when the metrics middleware is used.
func WithServer ¶ added in v1.1.2
WithServer returns the current server handling the request. It returns the server listening address: <scheme>://[<bind>]:<port> Normally this is something like "dns://:53", but if the bind plugin is used, i.e. "bind 127.0.0.53", it will be "dns://127.0.0.53:53", etc. If not address is found the empty string is returned.
Basic usage with a metric:
<metric>.WithLabelValues(metrics.WithServer(ctx), labels..).Add(1)
Types ¶
type Metrics ¶
type Metrics struct { Next plugin.Handler Addr string Reg *prometheus.Registry // contains filtered or unexported fields }
Metrics holds the prometheus configuration. The metrics' path is fixed to be /metrics
func (*Metrics) MustRegister ¶ added in v1.0.2
func (m *Metrics) MustRegister(c prometheus.Collector)
MustRegister wraps m.Reg.MustRegister.
func (*Metrics) OnFinalShutdown ¶ added in v1.1.2
OnFinalShutdown tears down the metrics listener on shutdown and restart.
func (*Metrics) RemoveZone ¶
RemoveZone remove zone z from m.