Install Nagios

Upgrade to Nagios 2.11 (Ubuntu Hardy Heron 8.04, from Edgy 6.10)

Names of the config files have changed, but content remains mainly the same. The config files reside at

/etc/nagios-plugins/config/

There are new service definitions for ssh access with ports different from the default port 21:

check_ssh_port!<port number>

The cgi directory has changed in the apt-get install, if you want to use the nagios checker plugin in firefox, use http://localhost/cgi-bin/nagios2/status.cgi

You might need to chown ownership of the existing backuppc directory if you did a clean install, as the user / group id's might not match the previous installation.

Also note that due to Gnome's virtual file system the disk space check on localhost will always return a critical error. To avoid this, replace the disk check script with return-ok in the services definition of localhost.

New install

Follow the instructions of this link: https://help.ubuntu.com/community/Nagios2 Add a symlink to access the stylesheets:

ln -s /etc/nagios2/stylesheets /usr/share/nagios2/htdocs/stylesheets

Administrator

htpasswd -c /etc/nagios2/htpasswd.users <user>

Config file

Add <user> to all config definitions with nagiosadmin (all are comma-delimited)

Create user

Following command creates the file htpasswd.users in /etc/nagios2:

htpasswd bco /etc/nagios2/htpasswd.users

Check nagios.cfg

/usr/sbin/nagios2 -v /etc/nagios2/nagios.cfg

Enable external commands

This is necessary to send commands to nagios through the web browser. You need to make the following changes to allow this:

Config file

File permissions

If you did not change the users of the default install, then nagios runs as user “nagios”, the apache web server runs as user “www-data”. Make the following changes to the file permissions to enable external commands.

chgrp www-data /var/lib/nagios2
chmod g+rwx /var/lib/nagios2/rw
chmod g+s /var/lib/nagios2/rw

Then, restart apache and nagios:

/etc/init.d/apache2 restart
/etc/init.d/nagios2 restart