How to setup Nagios Server on Redhat

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1. Don't install nagios using RPM,instead download the source code tarballs of both Nagios and the Nagios plugins (visit http://www.nagios.org/download/ for links to the latest versions).

wget http://osdn.dl.sourceforge.net/sourceforge/nagios/nagios-3.0.3.tar.gz

wget http://osdn.dl.sourceforge.net/sourceforge/nagiosplug/nagios-plugins-1.4.11.tar.gz

2. Create Account Information

Become the root user.

su -l

3. Create a new nagios user account and give it a password.

/usr/sbin/useradd -m nagios

passwd nagios

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

/usr/sbin/groupadd nagcmd

/usr/sbin/usermod -G nagcmd nagios

/usr/sbin/usermod -G nagcmd apache

5. Extract the Nagios source code tarball.

cd ~/downloads

tar xzf nagios-3.0.3.tar.gz

cd nagios-3.0.3

Run the Nagios configure script, passing the name of the group you created earlier like so:

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

6. Compile the Nagios source code.

# make all

Install binaries, init script, sample config files and set permissions on the external command directory.

# make install

# make install-init

# make install-config

# make install-commandmode

7. Customize Configuration

Sample configuration files have now been installed in the /usr/local/nagios/etc directory. These sample files should work fine for getting started with Nagios. You'll need to make just one change before you proceed...

Edit the /usr/local/nagios/etc/objects/contacts.cfg config file with your favorite editor and change the email address associated with the nagiosadmin contact definition to the address you'd like to use for receiving alerts.

vi /usr/local/nagios/etc/objects/contacts.cfg

8. Configure the Web Interface

Install the Nagios web config file in the Apache conf.d directory.

make install-webconf

root@lvs2 nagios-3.0.3]# make install-webconf

/usr/bin/install -c -m 644 sample-config/httpd.conf /etc/httpd/conf.d/nagios.conf

8. Create a nagiosadmin account for logging into the Nagios web interface.

htpasswd -c /usr/local/nagios/etc/htpasswd.users nagiosadmin

Restart Apache to make the new settings take effect.

service httpd restart

9. Compile and Install the Nagios Plugins

Extract the Nagios plugins source code tarball.

cd ~/downloads

tar xzf nagios-plugins-1.4.11.tar.gz

cd nagios-plugins-1.4.11

10. Compile and install the plugins.

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

make

make install

Start Nagios

11. Add Nagios to the list of system services and have it automatically start when the system boots.

chkconfig --add nagios

chkconfig nagios on

Verify the sample Nagios configuration files.

/usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg

If there are no errors, start Nagios.

service nagios start

12. Object configuration files

As mentioned, when the configuration files are split up, Nagios reads the data from these files in order for it to process host and service checks across the network. Before I begin, detailed documentation of all of the options for the template based objects are located at the website.

# cd /usr/local/nagios/etc/objects/

# touch hostgroup.cfg hosts.cfg services.cfg

# vi localhost.cfg

Copy the Services Definitions

# vi services.cfg

Paste the Services Definitions

#vi localhost.cfg

Copy the Host Definitions

#vi hosts.cfg

Paste the Host Definitions

#vi localhost.cfg

Copy the Host Definitions

# vi hostgroup.cfg

Paste the hostgroup Definitions

Setting up nagios.cfg

[me@rhel ~] cd /etc/nagios

[me@rhel nagios] mv localhost.cfg localhost.cfg_org

Turn on the allow commands to be executed from the CGI web interface.

[me@rhel nagios] vi nagios.cfg

# OBJECT CONFIGURATION FILE(S)

cfg_file=/etc/nagios/contacts.cfg

cfg_file=/etc/nagios/hostgroups.cfg

cfg_file=/etc/nagios/hosts.cfg

cfg_file=/etc/nagios/services.cfg

cfg_file=/etc/nagios/timeperiods.cfg

# EXTERNAL COMMAND OPTION

check_external_commands=1

# EXTERNAL COMMAND CHECK INTERVAL

command_check_interval=1

I have my sample config to download:http://www.turboupload.com/files/get/fS98EGYNwt/sampleconfig.odt