Using nagios4 as a babysitter for your envionment

Out of many different monitoring solutions, nagios is one of the most used solutions. The following article shall describe in brief, how to set up some useful monitoring tasks:

Defining custom checks

in /etc/nagios4/commands.cfg, you can define a custom command. Let’s do this with a http check, which evaluates the result and checks in this result for a regex:

define command {
 command_name check_http_host_regex
 command_line $USER1$/check_http -H $HOSTADDRESS$ -p $ARG1$ -u $ARG2$ -r $ARG3$ -t30

This check is to be called from your /etc/nagios4/$cfg_dir/your_host.cfg:

define service {
 use generic-service
 service_description nginx_http_result
 is_volatile 0
 notification_options c,r
 check_command check_http_host_regex!80!/foo.css!your_regex

After that, you can run nagios4 -v /etc/nagios4/nagios.cfg to verify, that your configuration is valid.