Creating a new command

In this recipe, we'll create a new command for a plugin that was just installed into the /usr/local/nagios/libexec directory in the Nagios Core server. This will define the way in which Nagios Core should use the plugin and thereby allow it to be used as part of a service definition.

Getting ready

You should have a Nagios Core 4.0 or newer server running with a few hosts and services configured already, and you should have a plugin installed for which you'd like to define a new command so that you can use it as part of a service definition. In this instance, we'll define a command for an installed check_rsync plugin.

How to do it...

We can define a new command in our configuration as follows:

1. Change to the directory containing the command configuration files for Nagios Core. The default file is commands.cfg, located in /usr/local/nagios/etc/objects:

   # cd /usr/local/nagios/etc/objects
   

2. Edit the commands.cfg file:

   # vi commands.cfg
   

3. At the bottom of the file, add the following...