Installing Nagios on Ubuntu 18.04

Nagios is a powerful open-source monitoring system that allows you to identify and resolve IT infrastructure problems before they can impact critical business processes. It provides monitoring and alerting for servers, network devices, applications, and services.

Here are the steps to install Nagios on Ubuntu 18.04:

Step 1: Update System Packages

Before starting the installation process, it's recommended to update the system packages to their latest versions:

sudo apt update
sudo apt upgrade

Step 2: Install Dependencies

Nagios has several dependencies that need to be installed first:

sudo apt install build-essential apache2 php openssl perl make php-gd libgd-dev libapache2-mod-php libperl-dev libssl-dev daemon wget apache2-utils unzip

Step 3: Create Nagios User and Group

Create a new user and group for Nagios:

sudo useradd nagios
sudo groupadd nagcmd
sudo usermod -aG nagcmd nagios
sudo usermod -aG nagios,nagcmd www-data

Step 4: Download and Compile Nagios

Download and extract Nagios source code:

wget https://github.com/NagiosEnterprises/nagioscore/archive/nagios-.tar.gz
tar -xzf nagios-.tar.gz
cd nagioscore-nagios-

Compile and install Nagios:

sudo ./configure --with-nagios-group=nagios --with-command-group=nagcmd
sudo make all
sudo make install
sudo make install-commandmode
sudo make install-init
sudo make install-config
sudo make install-webconf

Step 5: Set Nagios Admin Password

Set a password for the Nagios admin user:

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

Step 6: Start Nagios Service

Start the Nagios service and enable it to automatically start on boot:

sudo systemctl start nagios
sudo systemctl enable nagios

Congratulations! You have successfully installed Nagios on Ubuntu 18.04.