icinga2/doc/3.05-using-templates.md

Using Templates

Templates may be used to apply a set of similar settings to more than one object.

For example, rather than manually creating a ping service object for each of your hosts you can use templates to avoid having to copy & paste parts of your configuration:

template Service "generic-service" {
  max_check_attempts = 3,
  check_interval = 5m,
  retry_interval = 1m,
  enable_perfdata = true
}

apply Service "ping4" {
  import "generic-service",
  check_command = "ping4",
  assign where host.macros.address
}

apply Service "ping6" {
  import "generic-service",
  check_command = "ping6",
  assign where host.macros.address6
}

In this example both ping4 and ping6 services inherit properties from the template generic-service.

Objects as well as templates themselves can import an arbitrary number of templates. Attributes inherited from a template can be overridden in the object if necessary.