June 22, 2009 | By Fabio Milano In CentOS, Nagios, Tutorial |

Installing Nagios server and network monitoring on Centos 5 server

The official documentation can be found at http://support.nagios.com/knowledge-base/official-documentation .

Install necessary packages

yum install httpd gcc glibc glibc-common gd gd-devel php

Create Nagios User account and group

useradd -m nagios

Create nagcmd group for allowing external commands to be submitted through the web interface. Add both the nagios user and the apache user

groupadd nagcmd
usermod -a -G nagcmd nagios
usermod -a -G nagcmd apache
Create Directory to store Nagios installation files

mkdir /opt/Nagios

Download Nagios and Plugins

Save file to directory /opt/Nagios
http://www.nagios.org/download/download.php
As of this writing Nagios 3.0.6 (Stable) and Nagios Plugins 1.4.13 (Stable)

Extract Files:
cd /opt/Nagios
tar xzf nagios-3.0.6.tar.gz
cd nagios-3.0.6

Compile and Configure Nagios

./configure --with-command-group=nagcmd

Compile Nagios:

make all

Compile binaries, init script, sample config files:

make install
make install-init
make install-config
make install-commandmode

** Do Not Start Nagios **
Nagios has now been installed to the directory /usr/local/nagios/

Install Nagios Web Interface:
make install-webconf

Nagios Web Interface installed to /usr/local/nagios/share ( http conf file added to /etc/httpd/conf.d/nagios.conf )

Create Web Interface Login User:
** This is not the most secure method **
We will create user “nagiosadmin” ( remember the password you assign !)
htpasswd -c /usr/local/nagios/etc/htpasswd.users nagiosadmin

Restart Apache:

service httpd restart
Install Nagios Plugins

Extract Files:
cd /opt/Nagios
tar xzf nagios-plugins-1.4.13.tar.gz
cd nagios-plugins1.4.13

Compile and Configure Nagios Plugins

./configure --with-nagios-user=nagios --with-nagios-group=nagios
make
make install

Configure nagiosadmin email address for alerts

vi /usr/local/nagios/etc/objects/contacts.cfg
email nagios@localhost ; <<***** CHANGE THIS TO YOUR EMAIL ADDRESS ******

Verify the sample Nagios configuration files

/usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg
Total Warnings: 0
Total Errors: 0

Start Nagios

Enable Nagios to start at system startup / boot
chkconfig --add nagios
chkconfig nagios on
chkconfig httpd on

Start Nagios

service nagios start
Log into Web Interface