Nagios installation in Centos/Redhat

In this post, I will be explaining the step by step installation procedure of nagios.

This procedure is tested in Redhat and Centos based systems.

Step1: Install packages
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I am assuming here that, you server is installed fresh and you need need to install apache/PHP fresh.

So, download the packages and install them as below:
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yum install httpd php php-cli gcc glibc glibc-common gd gd-devel net-snmp
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Step2: Start the service
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service httpd start
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Step3: Setup user accounts
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useradd nagios
passwd nagios
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Step 4: Create a new group "nagcmd" and as the user "nagios" to the new group.
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 usermod -a -G nagcmd nagios
 usermod -a -G nagcmd apache
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Step 5:Install core-services of nagios. Follow the steps below:
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cd /opt/
wget http://prdownloads.sourceforge.net/sourceforge/nagios/nagios-4.0.7.tar.gz
tar xzf nagios-4.0.7.tar.gz
cd nagios-4.0.7
./configure --with-command-group=nagcmd
make all
make install
make install-init
make install-config
make install-commandmode
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Step 6:Run the below command to setup apache configuration.
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make install-webconf
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Step 7: Configure authentication of nagios and restart apache.
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htpasswd -c /usr/local/nagios/etc/htpasswd.users nagiosadmin
service apache restart
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Step 8: Install Nagios Plugins.
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cd /opt
wget http://nagios-plugins.org/download/nagios-plugins-2.0.3.tar.gz
tar xzf nagios-plugins-2.0.3.tar.gz
cd nagios-plugins-2.0.3
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Step 9: Now,compile and install nagios.
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./configure --with-nagios-user=nagios --with-nagios-group=nagios
make
make install
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Step 10: Verify and start nagios.
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/usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg
service nagios start
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Add the service to chkconfig:
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chkconfig --add nagios
chkconfig nagios on
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Step 11: Now, access the nagios interface via URL:
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http://ipaddress/nagios
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Now, you have configured nagios.

Regarding the plugins and nagios management, I will be writing a separate post.

Keep reading :)