metrics.names

metrics.names configures the template for the route metric names. The value is expanded by the text/template package and provides the following variables:

  • Service: the service name
  • Host: the host part of the URL prefix
  • Path: the path part of the URL prefix
  • TargetURL: the URL of the target

The following additional functions are defined:

  • clean: lowercase value and replace . and : with _

Given a route rule of

route add testservice www.example.com/ http://10.1.2.3:12345/

the template variables are:

.Service = testservice
.Host = www.example.com
.Path  = /
.TargetURL.Host = 10.1.2.3:12345

which results to the following metric name when using the default template:

testservice.www_example_com./.10_1_2_3_12345

The default is

metrics.names = {{clean .Service}}.{{clean .Host}}.{{clean .Path}}.{{clean .TargetURL.Host}}