Installing Nagios core on RHEL / CENTOS 5.x – RHEL / CentOS 6.x Fedora 15/16/17/18/19/20
What is Nagios
An enterprise-class monitoring and alerting solution that provides organizations with extended insight of their IT infrastructure before problems affect critical business processes.
Requirements
We require following things for Installing Nagios:
These are Just Pre-requisites. We need them to other things work …
1. Apache and PhP (php is optional)
2. gcc, glib, glibc-common, gd and gd-devel
I am performing this whole task on RHEL 5 and nagios core.
Installation
( A ) Installing/checking Dependencies
As we know we get these repositories already installed, so let’s check whether they are installed or not!..
Its a major step so please don’t skip this
Invoke the terminal and write these command one by one:
1 To Check Apache/Http
rpm -qa | grep httpd
2. To Check the Gcc
rpm -qa | grep gcc
rpm -qa | grep glibc glibc-common
rpm -qa | grep gd gd-devel
If everythings come ok lets move ahead…if not install the package using
yum install httpd
yum install glibc glibc-common
yum install gd gd-devel
yum install httpd
( B ) Create User And Groups
We need to create a user Nagios and put it to group Nadmin
useradd -m Nagios passwd Nagios "Set the password for the user Nagios" groupadd Nadmin /usr/sbin/usermod -a -G Nadmin Nagios /usr/sbin/usermod -a -G Nadmin apache
Building And Installing Nagios
Everything set lets begin with installation
1 Download Nagios tar using: => wget http://prdownloads.sourceforge.net/sourceforge/nagios/nagios-3.2.0.tar.gz 2 Untar it anywhere => tar zxf nagios-3.2.0.tar.gz 3 Get into the directory => cd nagios-3.2.0 4 configure the nagios using this command => ./configure --with-command-group=Nadmin 5 Run Make commands to build up the files to install Nagios => make all 6 Then use make install to install the init scripts in directory /etc/rc.d/init.d => make install 7 Lets configure permission for holding external files => make install-init 8 Install sample config files which can be found later in /usr/local/Nagios/etc => make install-config 9 This for commandmode installation => make install-commandmode 10 Set your Email Id using: => vi /usr/local/Nagios/etc/objects/contacts.cfg
Installing Web Interface
After Nagios is Installed lets install the Web interface a key Utility
1 Install web interface => make install-webconf 2 Create web interface account. Using this we gonna login for management => htpasswd -c /usr/local/Nagios/etc/htpasswd.users nagiosadmin 3 Done lets start Apache => /sbin/service httpd restart
As we are done with installing both Nagios and web interface we are yet not completed everything…
What we need now Nagios plugin , so lets begin with that 
Installing and Configuring Nagios plugins
Download plugins by typing this command in the terminal => wget http://prdownloads.sourceforge.net/sourceforge/nagiosplug/nagios-plugins-1.4.14.tar.gz Untar the file => tar zxf nagios-plugins-1.4.14.tar.gz Change directory: => cd nagios-plugins-1.4.14 Lets configure it :) => ./configure --with-nagios-user=Nagios --with-nagios-group=Nadmin Again make the files for the installation process => make Install the plugins => make install
This is the second part of the Nagios installation Process
Now, we need to start the nagios
Here is the process for the same :
To make the nagios utility to work automatically use this: => /sbin/chkconfig --add nagios Turn the Nagios on :) => /sbin/chkconfig nagios on We need a check config file that can work for for auto start of nagios. To do that use => /usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg done?? Now start the service /sbin/service nagios start
So here we are done with the nagios installation and configuration ….
For the web interface :
type the following in the URL
http://localhost/nagios orr http://ip/nagios
I tried to write this tutorial as simple as a 2nd standard guy can configure it 🙂 just a joke
any questions ??? let me know…..