Nagios is a popular open source computer system and network monitoring software application. It watches hosts and services, alerting users when things go 
wrong and again when they get better.
Nagios was originally designed to run under Linux, but also runs well on other Unix variants. It is free software, licensed under the terms of the GNU General Public License version 2 as published by the Free Software Foundation.
Before to start, if you want to install Nagios in other linux distros, please check our previous posts.
To install and configure nagios in Sabayon/Gentoo please follow the steps as described bellow:
1- INSTALL NAGIOS
You can install Nagios in Sabayon using the following command:
emerge nagios nagios-plugins net-snmp
2- Make .htaccess and Place this file inside the /usr/share/nagios/htdocs and /usr/lib/nagios/cgi-bin directories.
AuthName "Nagios Access" AuthType Basic AuthUserFile /etc/nagios/auth.users Require valid-user
3- Creating the nagiosadmin user:
Use the following command to create the nagios admin user:
htpasswd2 -c /etc/nagios/auth.users nagiosadmin
4-Add nagios to apache group
usermod -a -G nagios apache
chown nagios:nagios /etc/nagios/auth.users
chown nagios:nagios /usr/share/nagios
5- Add Nagios Alias for Apache: (/etc/apache2/modules.d)
sabayon6 modules.d # vi 99_nagios3.conf
Add this lines :
<IfDefine NAGIOS>
ScriptAlias /nagios/cgi-bin/ /usr/lib/nagios/cgi-bin/
<Directory "/usr/lib/nagios/cgi-bin/">
AllowOverride AuthConfig
Options ExecCGI
Order allow,deny
Allow from all
</Directory>
Alias /nagios /usr/share/nagios/htdocs
<Directory "/usr/share/nagios/htdocs">
AllowOverride AuthConfig
Order allow,deny
Allow from all
</Directory>
</IfDefine>
6- Start Nagios and apache
# /etc/init.d/nagios start # /etc/init.d/apache2 start
Open the Browser http://ip/nagios or http://hostname/nagios and lopinf with your nagios admin created
If you have any question please comment this post or post in the forum. Thanks
