Many-to-many relationships in Icinga2

Icinga 2
1

So typically there are many-to-many relationships in an Icinga configuration most obviously between hosts and services.

It is possible to add a list of services to a host, or a list of hosts to a service, but both are suboptimal because to update the lists one has to look at several entries.

So in Icinga1 I used to have empty hostgroups, and then add them to hosts and services to link them, which makes maintaining configurations a lot easier. Fully described here:

Is there something similar possible in the Icinga2 syntax? If so please suggest how to do it.

2

you can use “service apply rules” and as a rule you can use a “hostgroup contains xyz”

apply Service "test" {
    import "someservice"

    assign where "test" in host.groups

}
3

Hi @Walex,

Thank you for sharing this. We use Icinga Director and it looks like it allows to do what you describe, and more.

Best regards, and welcome to the community,

Jean

4

you can use “service apply rules” and as a rule you can use a “hostgroup contains xyz”

Thanks, that is useful. Does that imply that I can have empty (without any hosts listed) hostgroup definitions and list the hostgroups of each host in the host definition?

I had considered using vars in a similar way instead of hostgroups, but I would prefer to use hostgroups.

5

yes, a host group can be empty

6

Little side note here:
Please do not use HostGroups to assign Services, in my experience these things should be separated.
HostGroups are best used to group host for display, I prefer to assign Services based on custom vars (called “data fields” in the director). This avoids some problem, with the restricted logic of hostgroups, which are basically a list of tags.
With custom vars you can build something like exclusive fields ("this host is running a linux kernel OR a windows kernel).