How To Install Nagios on openSUSE

Nagios is a powerful open-source monitoring system that helps organizations keep track of their IT infrastructure. In this comprehensive guide, we’ll walk you through the process of installing Nagios Core on openSUSE, step by step. Whether you’re a system administrator or an IT enthusiast, this tutorial will equip you with the knowledge to set up Nagios and start monitoring your network effectively.

Table of Contents

Introduction to Nagios and openSUSE

Nagios Core is a robust monitoring system that allows you to keep tabs on your servers, network devices, and services. It provides real-time alerts and comprehensive reports, making it an essential tool for maintaining a healthy IT environment. OpenSUSE, on the other hand, is a stable and user-friendly Linux distribution that serves as an excellent platform for hosting Nagios.

In this guide, we’ll cover the installation of Nagios Core 4.4.14 on openSUSE. The process involves several steps, from preparing your system to configuring Nagios for first use. Let’s dive in!

Prerequisites

Before we begin the installation process, ensure that your openSUSE system meets the following requirements:

A fresh installation of openSUSE (this guide is based on openSUSE 15.3, but should work for other recent versions)
Root or sudo access to the system
A stable internet connection for downloading packages
Basic familiarity with the Linux command line

Preparing the System

Updating the System

Start by updating your openSUSE system to ensure you have the latest packages:

sudo zypper update

Installing Required Packages

Install the necessary dependencies for Nagios Core:

sudo zypper install -t pattern devel_C_C++
sudo zypper install libopenssl-devel perl wget unzip apache2 apache2-utils php7 apache2-mod_php7 gd gd-devel libopenssl-devel

Starting and Enabling Apache

Start the Apache web server and enable it to run at boot:

sudo systemctl enable --now apache2.service
sudo systemctl status apache2.service

Downloading Nagios Core

Now, let’s download the Nagios Core source package:

cd /tmp
wget https://github.com/NagiosEnterprises/nagioscore/releases/download/nagios-4.5.6/nagios-4.5.6.tar.gz
tar xzf nagios-4.5.6.tar.gz
cd nagioscore-nagios-4.5.6/

Compiling and Installing Nagios Core

Configuring the Build

Configure the Nagios Core build:

./configure --with-httpd-conf=/etc/apache2/vhosts.d

Compiling Nagios

Compile the main program and CGIs:

make all

Creating Nagios User and Group

Create the Nagios user and group, and add the Apache user to the Nagios group:

sudo make install-groups-users
sudo usermod -a -G nagios wwwrun

Installing Nagios Binaries

Install the Nagios binaries, CGIs, and HTML files:

sudo make install

Installing the Service/Daemon

Install and configure the Nagios service:

sudo make install-daemoninit

Installing Command Mode

Set up the external command file:

sudo make install-commandmode

Installing Configuration Files

Install the sample configuration files:

sudo make install-config

Configuring Apache for Nagios

Installing Apache Configuration

Install the Apache configuration files for Nagios:

sudo make install-webconf

Enabling Apache Modules

Enable the necessary Apache modules:

sudo a2enmod rewrite
sudo a2enmod cgi

Creating Nagios Web User

Create a user for accessing the Nagios web interface:

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

Configuring Firewall

Allow inbound traffic on port 80 for the Nagios web interface:

sudo firewall-cmd --permanent --add-service=http
sudo firewall-cmd --reload

Installing Nagios Plugins

Installing Plugin Dependencies

Install the necessary packages for Nagios plugins:

sudo zypper install autoconf gcc glibc libgcrypt-devel make libopenssl-devel wget gettext gettext-runtime automake net-snmp perl-Net-SNMP

Downloading and Extracting Plugins

Download and extract the Nagios plugins:

cd /tmp
wget https://github.com/nagios-plugins/nagios-plugins/releases/download/release-2.4.12/nagios-plugins-2.4.12.tar.gz
tar zxf nagios-plugins-2.4.12.tar.gz
cd nagios-plugins-release-2.4.12/

Compiling and Installing Plugins

Compile and install the Nagios plugins:

./tools/setup
./configure
make
sudo make install

Verifying and Starting Nagios

Verifying Nagios Configuration

Check the Nagios configuration for any errors:

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

Starting Nagios Service

If there are no errors, start the Nagios service:

sudo systemctl start nagios.service

Enabling Nagios at Boot

Enable Nagios to start automatically at system boot:

sudo systemctl enable nagios.service

Accessing the Nagios Web Interface

You can now access the Nagios web interface by opening a web browser and navigating to:

http://your_server_ip/nagios

Install Nagios on openSUSE

Basic Nagios Configuration

Understanding Configuration Files

Nagios configuration files are located in the /usr/local/nagios/etc/ directory. The main configuration file is nagios.cfg, which includes other configuration files.

Adding Hosts and Services

To monitor hosts and services, you’ll need to edit the configuration files in the /usr/local/nagios/etc/objects/ directory. For example, to add a new host:

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

Add a new host definition:

define host {
    use                     linux-server
    host_name               new_host
    alias                   New Host
    address                 192.168.1.100
    max_check_attempts      5
    check_period            24x7
    notification_interval   30
    notification_period     24x7
}

Restarting Nagios After Configuration Changes

After making changes to the configuration, always verify and restart Nagios:

sudo /usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg
sudo systemctl restart nagios.service

Troubleshooting Common Issues

Configuration Errors

If you encounter configuration errors, carefully review the error messages provided by the verification command. Common issues include syntax errors or missing dependencies.

Permission Problems

Ensure that the Nagios user has the necessary permissions to access configuration and log files. You may need to adjust file permissions using chmod and chown commands.

Web Interface Access Issues

If you can’t access the web interface, check Apache’s error logs (/var/log/apache2/error_log) for clues. Ensure that Apache is running and that the Nagios configuration is properly loaded.

Updating Nagios

To update Nagios in the future, you’ll need to download the new source code and repeat the compilation and installation steps. Always back up your configuration files before updating.

Congratulations! You have successfully installed Nagios. Thanks for using this tutorial to install the latest version of the Nagios monitoring tool on the openSUSE system. For additional help or useful information, we recommend you check the official Nagios website.

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