Rocky Linux 8 Monitoring with NCPA in Nagios XI: A Complete Setup Guide

Ensuring the health and performance of your Rocky Linux 8 servers is crucial for maintaining a stable IT environment. The Nagios Cross-Platform Agent (NCPA) provides a powerful, secure, and efficient way to monitor system metrics in real time using a RESTful API. In this guide, you’ll learn how to install and configure NCPA on Rocky Linux 8, seamlessly integrating it with Nagios XI for proactive monitoring and insightful analytics.

Prerequisites

Before proceeding:

• A Rocky Linux 8 system with sudo/root access
• A Nagios XI server with NCPA Wizard enabled
• Internet access for package downloads
• Port 5693/TCP open in the firewall

Step 1: Install the Nagios Repository

To install NCPA using the Nagios repository:

sudo rpm -Uvh https://repo.nagios.com/nagios/8/nagios-repo-8-1.el8.noarch.rpm
sudo dnf clean all
sudo dnf update -y

Step 2: Install NCPA

Install the agent via the repository:

sudo dnf install ncpa -y

Verify installation:

rpm -q ncpa

Expected: ncpa-<version>.el8.x86_64

Step 3: Configure NCPA

Set your API token:

sudo nano /usr/local/ncpa/etc/ncpa.cfg

Locate:

community_string = mytoken

Replace with a strong, unique value:

community_string = Str0ngT0k3n

Save and exit (Ctrl+O, Enter, Ctrl+X in nano).

Step 4: Start and Enable NCPA

Enable and start the NCPA service:

sudo systemctl enable ncpa
sudo systemctl start ncpa
sudo systemctl status ncpa

Confirm it’s active (running).

Step 5: Configure Firewall

Allow traffic on TCP port 5693:

sudo firewall-cmd --zone=public --add-port=5693/tcp --permanent
sudo firewall-cmd --reload

Verify:

sudo firewall-cmd --list-ports

• Ensure 5693/tcp is listed.

Step 6: Test NCPA Access

Open your browser and go to:

https://<RockyLinux8-IP>:5693/

Accept the certificate warning and log in with your token.

Step 7: Add Rocky Linux 8 Host to Nagios XI

1. Log into Nagios XI

2. Go to Configure > Configuration Wizards

3. Select NCPA

4. Enter:

• IP: <RockyLinux8-IP>
• Token: Str0ngT0k3n

5. Choose metrics (CPU, Memory, Disk, etc.)

6. Apply the configuration

Common Issues & Fixes

NCPA Not Running

sudo journalctl -u ncpa --no-pager | tail -20
sudo systemctl restart ncpa

Host Down in Nagios XI

• Confirm firewall:

sudo firewall-cmd --list-ports

• Check service:

sudo systemctl status ncpa

Invalid Token

Ensure correct token in ncpa.cfg and restart:

sudo systemctl restart ncpa

Conclusion

You’ve now configured NCPA on Rocky Linux 8 for integration with Nagios XI. For further support:

• Nagios Support Forum
• Nagios Knowledgebase
• NCPA Install Docs