Tag: nagios

Just for my references. I made changes to it before, but I now added the comments to them (for custom notifications and acknowledgements):

define command{
        command_name    notify-host-by-email
        command_line    /usr/bin/printf "%b" "***** Nagios *****\n\nNotification Type: $NOTIFICATIONTYPE$\nComment: $NOTIFICATIONCOMMENT$\nHost: $HOSTNAME$\nState: $HOSTSTATE$\nAddress: $HOSTADDRESS$\nInfo: $HOSTOUTPUT$\n\nDate/Time: $LONGDATETIME$\n" | /usr/bin/mail -s "** $NOTIFICATIONTYPE$ Host Alert ($SHORTDATETIME$): $HOSTNAME$ is $HOSTSTATE$ **" $CONTACTEMAIL$
}
 
define command{
        command_name    notify-service-by-email
        command_line    /usr/bin/printf "%b" "***** Nagios *****\n\nNotification Type: $NOTIFICATIONTYPE$\nComment: $NOTIFICATIONCOMMENT$\nService: $SERVICEDESC$\nHost: $HOSTALIAS$\nAddress: $HOSTADDRESS$\nState: $SERVICESTATE$\n\nDate/Time: $LONGDATETIME$\n\nAdditional Info:\n\n$SERVICEOUTPUT$" | /usr/bin/mail -s "** $NOTIFICATIONTYPE$ Service Alert ($SHORTDATETIME$): $HOSTALIAS$/$SERVICEDESC$ is $SERVICESTATE$ **" $CONTACTEMAIL$
}
 
define command{
        command_name    notify-host-by-sms
        command_line    /usr/local/sbin/send-sms.sh -n $CONTACTPAGER$ -m "$HOSTNAME$: $NOTIFICATIONTYPE$, $HOSTSTATE$ ($NOTIFICATIONCOMMENT$)"
}
 
define command{
        command_name    notify-service-by-sms
        command_line    /usr/local/sbin/send-sms.sh -n $CONTACTPAGER$ -m "$SERVICEDESC$ on $HOSTNAME$ $NOTIFICATIONTYPE$ ($NOTIFICATIONCOMMENT$): $SERVICEOUTPUT$"
}

Here are some useful extra nagios commands I often use:

define command{
        command_name    notify-host-by-sms
        command_line    /usr/local/sbin/send-sms.sh -n $CONTACTPAGER$ -m "$HOSTNAME$: $HOSTSTATE$"
}
 
define command{
        command_name    notify-service-by-sms
        # Don't use service state, otherwise you only ever get to see 'critical' and not the reason.
        command_line    /usr/local/sbin/send-sms.sh -n $CONTACTPAGER$ -m "$SERVICEDESC$ on $HOSTNAME$: $SERVICEOUTPUT$"
}
 
define command{
        command_name    check_imaps
        command_line    /usr/lib/nagios/plugins/check_imap -H '$HOSTADDRESS$' --ssl -p 993 --certificate 15
}
 
define command{
        command_name    check_rdp
        command_line    /usr/local/lib/nagios/plugins/check_x224 -H $HOSTADDRESS$ -p $ARG1$ -w 10 -c 50
}
 
define command{
  command_name  check_pops
  command_line  /usr/lib/nagios/plugins/check_pop -H '$HOSTADDRESS$' --ssl -p 995 --certificate 15
}
 
define command{
  command_name  check_smtps
  command_line  /usr/lib/nagios/plugins/check_tcp -H $HOSTADDRESS$ -p 465
}

Nagios is an elaborate piece of software to monitor hosts and services. I will explain a bit how you can configure nagios to monitor an HTTP service. I’m assuming your nagios setup already has the default config files generic-host_nagios2.cfg and generic-service_nagios2.cfg, which tell nagios how to monitor hosts and services.

Most configuration is done in /etc/nagios3/conf.d. For some reason, the standard config files all end with _nagios2.cfg, so I guess this is old syntax. But, I don’t really know why these files are named that way.

Nagios comes with a bunch of default files to which you can add your hosts, services, etc.

First you have to define a host. If you’re monitoring on the machine itself, you could add a host to localhost_nagios2.cfg. Using the default localhost doesn’t work, because you need to access the machine using the address of the virtual host.

define host{
        use                     generic-host            ; Name of host template to use
        host_name               my-site
        address                 www.halfgaar.net
}

Then you need to define a hostgroup for your HTTP servers. A default HTTP hostgroup is probably already defined, so you can add your host to http-servers in hostgroups_nagios2.cfg

define hostgroup {
        hostgroup_name  http-servers        
        members         localhost, my-site # comma separated
}

Lastly, you need to configure a service. Nagios comes with a default one for the hostgroup http-servers so you should be done, but just in case:

define service {
        hostgroup_name                  http-servers
        service_description             HTTP
        check_command                   check_http
        use                             generic-service
        notification_interval           0 ; set > 0 if you want to be renotified
}