Christian’s blog

Nagios 3 and hostgroup inheritance

Posted on the August 8th, 2008 under Life by Christian

As I wrote some time ago, I was trying to utilize Nagios 3.x’s neat feature of “nested” hostgroups. Well, as it turned out I thought it worked differently; basically like this:

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define hostgroup {
        hostgroup_name      a-parent-hostgroup
        alias               Our toplevel parent hostgroup
}
 
define service {
       use                  generic-service
       check_command        check_dummy!0!
       service_description  SSH
       hostgroup_name       a-parent-hostgroup
}
 
define hostgroup {
        hostgroup_name      a-child-hostgroup
        hostgroup_members   a-parent-hostgroup
        alias               Our child hostgroup
}
 
define service {
       use                  generic-service
       check_command        check_dummy!0!
       service_description  LOAD
       hostgroup_name       a-child-hostgroup
}

As you can cleary see on line 14, I thought you define the relation between two hostgroups in the child hostgroup. The problem with it was basically (as I said in the earlier posts), that all the services defined for the child hostgroups are handed on upwards to the parent hostgroup(s).

But after talking to Tobi, I quickly found out, that the relation is in fact defined within the parent hostgroup. So if you simply put hostgroup_members within the parent hostgroup and define all child hostgroups which should inherit from the parent one, you should be just fine.