This tutorial shows how to send Nagios' notifications to an instant messaging client. The client has to be connected to a private Jabber server.

Here is a screenshot of Exodus, showing a Nagios message:

Jabber server

Jabberd 2 is an instant messaging server (open source), that supports chatting, messaging, and if corresponding plug-in is installed, chatrooms, etc. What we need here is only messaging. Jabber protocol is suported by many clients. As far as I'm concerned, Exodus for Windows works well.

To install Jabber, please refer to jabberstudio web site. It must be installed on the same Linux box that runs Nagios.

This tutorial works for the following versions :

• Jabberd v2.0 s4
• Nagios v2.4
• Exodus v 0.9.1.0

Server configuration

Jabber domain should match your internal DNS domain, so things will be simpler for clients configuration. All other settings were left to default.

Option: my server is configured so not to automatically register new users (it's not supposed to be a public general-purpose server). This is done in configuration file c2s.xml, item <register>: just comment <enable/> line. This settings implies manually creating users in mysql database. Here is a sample mysql command:

mysql -u jabberd2 -p 
   <mysql password>
mysql> use jabberd2
mysql> insert into authreg (username, realm, password) values ('login_name', 'your.jabber.domain', 'password');

And to delete a user:

mysql> delete from authreg where username='login_name';

Two accounts at least have to be created: yours (to connect your client) and "nagios" (who sends messages to you).

Connecting from a Jabber client

This concerns Exodus but can be easily transposed to any other client:

Profile tab

• Username : <login_name>
• Server : <your.jabber.domain>
• Resource : <we don't care>
• Password : <password>

Connection tab

• Host : <Jabber server full name>
• Port : 5222

In this tab, you also can use Jabber server automatic discovery. This is were domain matching comes into play. In your internal DNS server (Active Directory for me), add the following lines in _tcp subdomain:

• _jabber, type SRV, port number 5269, host <jabber server full name>
• _xmpp-server, type SRV, port number 5269, host <jabber server full name>
• _xmpp-client, type SRV, port number 5222, host <jabber server full name

Your jabber client will then ask your DNS where to find a jabber service. Nice, isn't it? Use your Jabber client to log in as "nagios" at least once, just to check its account works. Then log in as yourself.

Sending a message from Nagios

Message sending script

The script is written in Perl, so I tried using Perl module Net::Jabber. David Cox did that, and shares a script named notify_via_jabber.pl. You can find it at Nagios Exchange.

But I couldn't have that script to work. So I did something really bad: telnet on Jabber server's TCP port, and write Jabber commands. My script is called send_jabber.pl. Change the Jabber domain name "domaine.com" with yours if you plan to use this script.

Nagios Configuration

The following configuration works with my script send_jabber.pl.
First, create contacts in configuration file contacts.cfg. I personaly use a template, and an inherited contact:

define contact{
   name generic-contact
   register 0
   service_notification_period 24x7
   host_notification_period 24x7
   service_notification_options w,u,c,r
   host_notification_options d,u,r
   service_notification_commands notify-by-email
   host_notification_commands host-notify-by-email
   }

define contact{
   use generic-contact
   contact_name my-jabber-name
   alias Myself
   pager login_name@my.jabber.domain
   service_notification_commands notify-by-jabber
   host_notification_commands host-notify-by-jabber
   service_notification_period workhours
   host_notification_period workhours
   }

Notification commands are defined in misccommands.cfg, one for services notification, the other for hosts notification:

 define command{
   command_name notify-by-jabber
   command_line /usr/local/nagios/libexec/send_jabber.pl $CONTACTPAGER$ $NOTIFICATIONTYPE$ "$HOSTNAME$" "$SERVICEDESC$" "$SERVICESTATE$" "$OUTPUT$" "$DATETIME$"
   }

define command{
   command_name host-notify-by-jabber
   command_line /usr/local/nagios/libexec/send_jabber.pl $CONTACTPAGER$ $NOTIFICATIONTYPE$ "$HOSTNAME$" "" "$HOSTSTATE$" "$OUTPUT$" "$DATETIME$"
   }

You still need to associate that contact with a contactgroup, then put the contactgroup in the concerned host or service configuration. As a Nagios admin, you already know how to do this.