Some Nagios Notes for HTTP Monitoring

I needed to monitor some non-standard HTTP  ports with Nagios.  Installation went well, but it took a little fooling around to get the HTTP monitoring the way that I wanted.  [N. B. After writing this, I realized later that the default settings could probably do what I wanted.  But here it is anyway.]

First, make sure your check_http command is working correctly.  It is in $NAGIOS_HOME/plugins/check_http.  Use --help to see your options.  You'll note that there are several, but the actual command that Nagios runs is defined in the file commands.cfg.  The default is

# 'check_http' command definition

define command{

        command_name    check_http

        command_line    $USER1$/check_http -I $HOSTADDRESS$ $ARG1$

        }

I changed the command_line to

        command_line    $USER1$/check_http -I $ARG1$ -p $ARG2$

You could of course add additional options supported by check_http.

Next, you need to add hosts to be monitored.  I just appended these to localhost.cfg.  This is an example for monitoring http://my.machine.indiana.edu:9999 (with IP addres 123.456.789).

define host{

        use             linux-server            ; Name of host template to use

        host_name       my-machine       ; The name we're giving to this host

        alias           CICC Tomcat     ; A longer name associated with the host

        address         123.456.789           ; IP address of the host

        hostgroups      linux-servers           ; Host groups this host is associated with

        }

define service{
        use             local-service         ; Name of service template to use

        host_name       my-machine

        service_description     HTTP

        check_command   check_http!my.machine.indiana.edu!9999
        notifications_enabled           0

        }

That's it.  Maybe there is a better way to do this but I could not find it easily.