Nagios Core Installation on CentOS Stream 10

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Nagios Core is a powerful open-source monitoring system that enables users to monitor network infrastructure, servers, and applications. This document provides step-by-step instructions for installing Nagios Core on CentOS Stream 10.

Prerequisites

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• A system running CentOS Stream 10
• LAMP Stack installed and running, for this, you can refer to one of our guides on installing the LAMP Stack (Apache, MariaDB, and PHP) .
• root or sudo privileges

Install Required Dependencies

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Update the system and install necessary packages:

dnf update -y
dnf install -y gcc glibc glibc-common perl pcre2-devel wget unzip autoconf gcc-c++ make curl libpng-devel libjpeg-devel gd-devel perl-DBI openssl-devel

Download and Install Nagios Core

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Download the latest version of Nagios Core:

cd /tmp
dnf install wget -y
wget https://github.com/NagiosEnterprises/nagioscore/releases/download/nagios-4.5.9/nagios-4.5.9.tar.gz

Extract the downloaded archive:

dnf install tar -y
tar xzf nagios-4.5.9.tar.gz
ls -lah
cd nagios-4.5.9

Create the Nagios User and Group

useradd nagios
groupadd nagcmd
usermod -aG nagcmd nagios
usermod -aG nagcmd $(whoami)  # Add your current user to the nagcmd group

Now, verify that the user exists:

id nagios

make clean
./configure --with-command-group=nagios
make all

make install
make install-init
make install-config
make install-webconf
make install-commandmode

Install Nagios Plugins

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cd /tmp
wget https://github.com/nagios-plugins/nagios-plugins/releases/download/release-2.4.12/nagios-plugins-2.4.12.tar.gz
tar xzf nagios-plugins-2.4.12.tar.gz
cd nagios-plugins-2.4.12
./configure --with-nagios-user=nagios --with-nagios-group=nagios
make
make install

Verify Installation After installation, check if the plugins were installed:

ls /usr/local/nagios/libexec/

You should see plugin files like check_ping, check_http, etc.

Set Up Web Interface Authentication

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Create a login password for the Nagios web interface:

mkdir -p /usr/local/nagios/etc
chown -R nagios:nagios /usr/local/nagios
chmod -R 775 /usr/local/nagios

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

Restart Apache:

systemctl restart httpd

Start and Enable Nagios

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systemctl enable nagios
systemctl start nagios

Access Nagios Web Interface

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Open a web browser and navigate to:

http://Your_Server_IP/nagios

Note: Replace the "Your_Server_IP" with actual IP Address

Log in using:

• Username: nagiosadmin
• Password: (the one you set earlier)

Conclusion

You have successfully installed Nagios Core on CentOS Stream 10. You can now configure hosts and services to monitor your network efficiently. For further configuration, refer to the official Nagios documentation: https://www.nagios.org/documentation/