Install and Configuration of NAGIOS

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:
      1. Apache and PhP (php is optional)
      2. gcc, glib, glibc-common, gd and gd-devel
             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 plesase 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 :

   3.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

( 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/nagio
s/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 (install Server and Client)
Note:      Nagios Plugins in installed only and client side Nagios core not install
in Client side.

Download plugins by typing this command in the terminal
=> wget
http://prdownloads.sourceforge.net/sourceforge/nagio
splug/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
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