How to Setup Nagios 3.4.4 Network Monitoring On Ubuntu Server 12.04/12.10

This guide will shown you how to installing latest version of nagios 3.4.4 on Ubuntu Server 12.04/12.10. Nagios is free and open source tool with GPL License allowing to control and monitor the items and services on a network. When it detects a problem it sends alert messages, either by mail or by other techniques.

Step 1. Before installing Nagios 3.4.4 on Ubuntu Server 12.04/12.10, make sure your Ubuntu Server is up to date. Enter the following commands one by one, and install any available updates:

sudo apt-get update

sudo apt-get upgrade -y

Step 2.  Install Apache 2, PHP5, GCC ( development libraries and compilation), GD ( development libraries) on other package

sudo apt-get install build-essential apache2 php5-gd wget libgd2-xpm libgd2-xpm-dev libapache2-mod-php5 libssl-dev

Step 3. Create users and groups for Nagios:

sudo mkdir -p /etc/nagios /var/nagios

sudo groupadd --system --gid 9000 nagios

sudo groupadd --system --gid 9001 nagcmd

sudo adduser --system --gid 9000 --home /usr/local/nagios nagios

sudo usermod --groups nagcmd nagios

sudo usermod --append --groups nagcmd www-data

sudo chown nagios:nagios /usr/local/nagios /etc/nagios /var/nagios

Step 4. Download the source code of both compressed Nagios and the Nagios plugins (visit http://www.nagios.org/download/ for links to the latest versions). At time of writing, the latest versions of Nagios 3.4.4 and the Nagios plugins 1.4.16

cd /usr/local/src/

wget http://sourceforge.net/projects/nagios/files/nagios-3.x/nagios-3.4.4/nagios-3.4.4.tar.gz

wget http://sourceforge.net/projects/nagiosplug/files/nagiosplug/1.4.16/nagios-plugins-1.4.16.tar.gz

Step 5. Extract, Compile and Install source of nagios 3.4.4

sudo tar -xzvf /usr/local/src/nagios-3.4.4.tar.gz

cd /usr/local/src/nagios

sudo ./configure --sysconfdir=/etc/nagios --localstatedir=/var/nagios --prefix=/usr/local/nagios --with-nagios-user=nagios --with-nagios-group=nagios --with-command-group=nagcmd --with-openssl=/usr/bin/openssl --enable-perl-modules --with-mail=/usr/bin/sendemail

sudo make all

sudo make install

sudo make install-init

sudo make install-config

sudo make install-commandmode

Step 6. Edit file /etc/objects/contacts.cfg to change the email address that is associated with nagiosadmin contact with the email address where you want to be alerted.

sudo nano /etc/objects/contacts.cfg

Example:

define contact{
               contact_name   nagiosadmin ;
               use            generic-contact ;
               alias          Ubuntu Precise ;
               email          admin@ubuntuprecise.net ;
}

Step 7. Edit file /etc/nagios/objects/commands.cfg to change both sendemail references to match the correct sendemail syntax:

sudo nano /etc/nagios/objects/commands.cfg

define command{
 command_name notify-host-by-email
 command_line /usr/bin/printf "%b" "***** Nagios *****\n\nNotification Type: $NOTIFICATIONTYPE$\nHost: $HOSTNAME$\nState: $HOSTSTATE$\nAddress: $HOSTADDRESS$\nInfo: $HOSTOUTPUT$\n\nDate/Time: $LONGDATETIME$\n" | /usr/bin/sendemail -s srv-mail:25 -f "admin <admin@ubuntuprecise.net>" -t $CONTACTEMAIL$ -u "** $NOTIFICATIONTYPE$ Host Alert: $HOSTNAME$ is $HOSTSTATE$ **"
}
define command{
command_name notify-service-by-email
command_line /usr/bin/printf "%b" "***** Nagios *****\n\nNotification Type: $NOTIFICATIONTYPE$\n\nService: $SERVICEDESC$\nHost: $HOSTALIAS$\nAddress: $HOSTADDRESS$\nState: $SERVICESTATE$\n\nDate/Time: $LONGDATETIME$\n\nAdditional Info:\n\n$SERVICEOUTPUT$" | /usr/bin/sendemail -s srv-mail:25 -f "admin <admin@ubuntuprecise.net>" -t $CONTACTEMAIL$ -u "** $NOTIFICATIONTYPE$ Service Alert: $HOSTALIAS$/$SERVICEDESC$ is $SERVICESTATE$ **"
}

Step 7. Now we need to configure Nagios to access it via web interface.

• Install the web configuration file in the Apache conf.d directory:

cd /usr/local/src/nagios

sudo make install-webconf

• Create password for Account nagiosadmin to enter the Nagios web interface. Remember the password you assign to this account – you will need it later. then restart apache2 daemon

sudo htpasswd -c /etc/nagios/htpasswd.users nagiosadmin

sudo /etc/init.d/apache2 reload

• Edit file /etc/apache2/apache2.conf and add the following line:

sudo nano /etc/apache2/apache2.conf

DirectoryIndex index.html index.php index.cgi

Step 8. Check your Nagios 3.4.4 configuration file for errors by typing following command. Look for errors in red

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

Step 9. Extract, Compile and install Nagios Plugins 1.4.16

cd /usr/local/src

wget http://prdownloads.sourceforge.net/sourceforge/nagiosplug/nagios-plugins-1.4.16.tar.gz

sudo tar -zxvf /usr/local/src/nagios-plugins-1.4.16.tar.gz

cd /usr/local/src/nagios-plugins-1.4.16

sudo ./configure --sysconfdir=/etc/nagios --localstatedir=/var/nagios --with-nagios-user=nagios --with-nagios-group=nagios

sudo make

sudo make install

Step 10. Set Nagios is started whenever the system boots up, then restart nagios daemon

sudo /usr/sbin/update-rc.d -f nagios defaults 99

sudo ln -s /etc/init.d/nagios /etc/rcS.d/S99nagios

sudo /etc/init.d/nagios restart

If all goes well, we should now be able to enter a Web browser to access Nagios administrator panel. Open a web browser and enter:

http://domain/nagios/

We ask for the username (nagiosadmin) with the password you have chosen in step 7.  If all went well you should see the home page of Nagios Administrator Panel

Link Reference:

• Nagios Basic Installation for Ubuntu
• Nagios Ubuntu Wiki
• Nagios Support Portal
• Nagios Community Wiki