Once you've edited the configuration files make sure to tell Icinga 2 to validate the configuration changes. Icinga 2 will log any configuration error including a hint on the file, the line number and the affected configuration line itself.

The following example creates an apply rule without any assign condition.

 apply Service "5872-ping4" {
 import "generic-service"
 check_command = "ping4"
 //assign where match("5872-*", host.name)
 }

Validate the configuration with the init script option checkconfig:

 # /etc/init.d/icinga2 checkconfig

You can also use the CLI command icinga2 object list after validation passes to analyze object attributes, inheritance or created objects by apply rules.

Example filtered by Service objects with the name ping*:

  # icinga2 object list --type Service --name *ping*
Object 'nbmif.int.netways.de!ping4' of type 'Service':
  * __name = 'nbmif.int.netways.de!ping4'
  * check_command = 'ping4'
  % = modified in '/etc/icinga2/conf.d/services.conf', lines 17:3-17:25
  * check_interval = 60
  % = modified in '/etc/icinga2/conf.d/templates.conf', lines 28:3-28:21
  * host_name = 'nbmif.int.netways.de'
  % = modified in '/etc/icinga2/conf.d/services.conf', lines 14:1-14:21
  * max_check_attempts = 3
  % = modified in '/etc/icinga2/conf.d/templates.conf', lines 27:3-27:24
  * name = 'ping4'
  % = modified in '/etc/icinga2/conf.d/services.conf', lines 14:1-14:21
  * retry_interval = 30
  % = modified in '/etc/icinga2/conf.d/templates.conf', lines 29:3-29:22
  * templates = [ 'ping4', 'generic-service' ]
  % += modified in '/etc/icinga2/conf.d/services.conf', lines 14:1-14:21
  % += modified in '/etc/icinga2/conf.d/templates.conf', lines 26:1-30:1
  * type = 'Service'
  * vars
  % += modified in '/etc/icinga2/conf.d/services.conf', lines 18:3-18:19
  * sla = '24x7'
    % = modified in '/etc/icinga2/conf.d/services.conf', lines 18:3-18:19