Nagios XI - How To Test Check Commands From The Command-line

Overview

This guide explains how to test check commands from command line in Nagios XI.

While there is the Test Check Command button in Core Configuration Manager (CCM), this does not always work as expected due to:

• PHP character escaping for special characters
• It is executed as the apache user instead of the nagios user

Due to these limitation, testing some check commands really need to be done at the command line as the nagios user.

Determining Check Command

You will need to go through a few steps to establish what exactly is being run. Grab some paper to note settings as you go.

Start by going to Configure > Core Config Manager.

Under Monitoring > Services in the left sidebar, find the service in question, and click the crossed tools Configure icon.

On the Common Settings tab, note what it says for Command view and the values of the eight ARG variables

• If these fields are empty, the command and values are being inherited by a template
• Click the Manage Templates button and make note of the template being used
• Now, in the left sidebar again, click Templates > Service templates, and find any that were listed on the previous step
• Make note what it says for Command view and the values of the eight ARG variables

At this point you should now know what check command is used along with the variable values.

Now, starting with what you had for Command view, replace $USER1$ with /usr/local/nagios/libexec and replace $HOSTADDRESS$ with the IP address of the host this service is associated with.

As an example:

• I have a host called Server Room, with an IP address of 192.168.5.254 and it has a simple ping check
• For Check command and Command view they're blank and for templates it has xiwizard_websensor_ping_service
• The template for xiwizard_websensor_ping_service has a Check command of check_xi_service_ping and a Command view of:
  • $USER1$/check_icmp -H $HOSTADDRESS$ -w $ARG1$,$ARG2$ -c $ARG3$,$ARG4$ $ARG5$
• With the arguments:
  • $ARG1$ = 3000.0
  • $ARG2$ = 80%
  • $ARG3$ = 5000.0
  • $ARG4$ = 100%
  • $ARG5$ = -p 8

Now, starting with what you had for Command view, replace $USER1$ with /usr/local/nagios/libexec and replace $HOSTADDRESS$ with the IP address of the host this service is associated with which is 192.168.5.254 :

• /usr/local/nagios/libexec/check_icmp -H 192.168.5.254 -w $ARG1$,$ARG2$ -c $ARG3$,$ARG4$ $ARG5$

All you need to do is match up the $variables$ with the values from the fields:

• /usr/local/nagios/libexec/check_icmp -H 192.168.5.254 -w 3000.0,80% -c 5000.0,100% -p 8
  

That's your full check command.

Now, log into your Nagios XI server as root, either on a direct terminal or through SSH. Enclose your command in single quotes, put su -c before it and nagios after it, and hit enter. It should look something like this:

Type:

su -c '/usr/local/nagios/libexec/check_icmp -H 192.168.5.254 -w 3000.0,80% -c 5000.0,100% -p 8' nagios

This is the output message from running the command:

OK - 192.168.5.254: rta 50.903ms, lost 0%|rta=50.903ms;3000.000;5000.000;0; pl=0%;80;100;;

Obviously that will be filled in with different details based on the check you're trying to run, but hopefully that demonstrates the progression of how to build the line.

If you experience any errors, the errors should help you fix your check command. Once you've got the check command working from the command line, go back into CCM and update the relevant fields to resolve the problem.

Final Thoughts

For any support related questions please visit the Nagios Support Forums at:

http://support.nagios.com/forum/