Nagios is network monitoring tool. In this tutorial, we will learn how to Install and configure Nagious 4 on Centos / RHEL 8. Nagious is configured using text files & provides web interface for ease to use for administration and Monitoring. Just follow these steps to quickly install & configure Nagious 4:
Pre-requisites:
- SELinux (Passive mode):
sudo sed -i 's/SELINUX=.*/SELINUX=permissive/g' /etc/selinux/config
sudo setenforce 0
Step 1: Installing Dependencies
Update your system.
sudo dnf updates
Install required Dependencies.
sudo dnf install @php
sudo dnf install @perl @httpd wget unzip glibc automake glibc-common gettext autoconf php php-cli gcc gd gd-devel net-snmp openssl-devel unzip net-snmp postfix net-snmp-utils
Guide for Installing Development Tools on RHEL 8 / Cento 8.
sudo dnf groupinstall "Development Tools"
Now, start and enable httpd and php-fpm services.
sudo systemctl enable --now httpd php-fpm
Checki status is running.
systemctl status http php-fpm
Detailed instructions for the Installation of PHP and httpd.
Step 2: Downloading Nagios Core
Change directory to /usr/src/. Go to latest-release page of Nagios to download.
sudo su -
cd /usr/src
Create nagios-$VER directory.
Download & extract Nagios tarball.
https://github.com/NagiosEnterprises/nagioscore/releases
Change path to created folder.
cd nagios-$VER
Step 3: Compile Nagios Core on Centos 8 / RHEL 8.
a. Run the configure script by command below:
./configure
Output:
b. To compile the main program and CGIs, run the make command with all options.
sudo make all
Output:
c. Create User And Group
This will create user and groups in Nagios
Add apache user to Nagios Group.
make install-groups-users
usermod -a -G nagios apache
d. Install Nagios on Centos / RHEL 8.
Install Nagios base.
make install
e. Install the init script in /lib/systemd/system.
make install-init
f. Install and configure the permissions on the directory for holding the external command file.
make install-commandmode
g. Install sample config files in /usr/local/nagios/etc.
make install-config
h. Install the Apache config file for the Nagios web interface.
make install-webconf
i. Install the Exfoliation theme for the Nagios web interface.
make install-exfoliation
j. You can install classic theme for Nagios web interface by given command
make install-classicui
Step 4: Creating Nagios Web User
We need to create a user account for Nagios web interface . Use the given command:
sudo htpasswd -c /usr/local/nagios/etc/htpasswd.users nagiosadmin
Restart Apache services to take effect.
systemctl restart httpd
Step 5: Installing Nagios Plugins
Plugins are used to provide more monitoring features.
Switch to /usr/src directory.
cd /usr/src
Create new directory as nagios-plugins-$VER
mkdir nagios-plugins-$VER
Download Nagios plugins from Github releases page.
Extract it to /usr/src/nagios-plugins-$VER directory.
Now, change directory to nagios-$VER.
cd 'nagios-$VER'
Use this command to install and compile Nagios Plugins.
./configure --with-nagios-user=nagios --with--nagios-group=nagios
make && make install
Output:
Step 6: Verifying Installation & Starting Nagios Services.
Make sure your Nagios installation is working properly.
/usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg
Start & Enable Nagios service to start at boot.
sudo systemctl enable --now nagios
Re-check the service status.
systemctl status nagios
Step 7: Accessing Nagios Web Dashboard
Remove firewall restrictions:
sudo firewall-cmd --permanent --add-service={http,https}
sudo firewall-cmd --reload
Access Dashboard by visiting http:[IP/hostname]/nagios/
Fill out Authentication details:
Username: nagiosadmin
You can add device to be monitored in Dashboard.
