How to Install Nagios on Debian 10

In this article, we will have explained the necessary steps to install and set up Nagios on Debian 10. Before continuing with this tutorial, make sure you are logged in as a user with sudo privileges. All the commands in this tutorial should be run as a non-root user.

Nagios is an open-source tool that gives an enterprise-class central monitoring engine regarding IT monitoring, network monitoring, server in addition to applications monitoring. It also provides the web interface for viewing current position, historical logs, and basic reports.

Install Nagios on Debian 10

Step 1. The first command will update the package lists to ensure you get the latest version and dependencies.

sudo apt update
sudo apt upgrade
sudo apt install build-essential unzip openssl libssl-dev apache2 php libapache2-mod-php php-gd libgd-dev

Step 2. Create User And Group for Nagios.

Now create a dedicated Nagios user and group:

sudo make install-groups-users
sudo usermod -a -G nagios www-data

Step 3. Install Nagios on the Debian system.

Go to the official website for downloading the latest version of Nagios Core:

wget https://assets.nagios.com/downloads/nagioscore/releases/nagios-4.4.6.tar.gz
tar -zxvf nagios-4.4.6.tar.gz 
cd /tmp/nagios-4.4.6/

Then, compile Nagios from the source code:

sudo ./configure --with-nagios-group=nagios --with-command-group=nagcmd --with-httpd_conf=/etc/apache2/sites-enabled/
sudo make all
sudo make install
sudo make install-init
sudo make install-config
sudo make install-commandmode
sudo make install-webconf

Step 4. Configure Nagios.

Now edit /usr/local/nagios/etc/objects/contacts.cfg file for nagiosadmin before you start the Nagios server:

sudo nano /usr/local/nagios/etc/objects/contacts.cfg

Change to the email address of your choice to receive the notification:

define contact{
        contact_name                    nagiosadmin             ; Short name of user
        use                             generic-contact         ; Inherit default values from generic-contact template (defined above)
        alias                           Nagios Admin            ; Full name of user

        email                           [email protected] ; <<-- CHANGE THIS TO YOUR EMAIL ADDRESS

        }

Step 5. Configure Nagios Web Interface.

Now create a user nagiosadmin account for logging into the Nagios web interface:

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

Restart Apache web service to make the new settings take effect:

sudo a2enmod cgi
sudo systemctl restart apache2

Step 5. Install Nagios Plugins.

Download and install Nagios plugins using the following commands:

cd /tmp
wget https://nagios-plugins.org/download/nagios-plugins-2.2.1.tar.gz
tar -zxvf /tmp/nagios-plugins-2.2.1.tar.gz
cd /tmp/nagios-plugins-2.2.1/

Then, compile and install the plugins:

sudo ./configure --with-nagios-user=nagios --with-nagios-group=nagios
sudo make
sudo make install

Once done, start Nagios monitoring tool using the following command:

sudo systemctl start nagios
sudo systemctl enable nagios
sudo systemctl status nagios

Step 6. Configure Firewall.

In case you have a firewall running, please allow the necessary ports:

sudo ufw allow 80/tcp
sudo ufw reload
sudo ufw enable

Step 7. Access Nagios Web Interface.

Now access the Nagios web interface by going following URL in your web browser:

http://your-ip-address/nagios/

That’s all you need to do to install the Nagios on Debian 10 Buster. I hope you find this quick tip helpful. For further reading on Nagios monitoring tools, please refer to their official knowledge base. If you have questions or suggestions, feel free to leave a comment below.