Prerequisites

The only prerequisite for setting up is installing the curl command. curl is a versatile tool used in Linux systems to transfer data from or to a server, supporting a variety of protocols such as HTTP, HTTPS, FTP, and more. It’s commonly used to download files, make API requests, or test network connections. To install curl we will need sudo or root permissions and use the command:

sudo apt install curl

As long as you get some form of output you now have curl installed.

Step 1: Run Commands listed in Log Server

The exact commands we need to use in our instance of Debian 10 are listed inside of Nagios LS, so we will be going there and looking at the commands needed. To do this we will want to add a log source, specifically a Linux source. We will want to click the circled area in the image below and select to add a Linux source.

Now there are instructions here, we will be going over them as well as their intended output. The first command is:

curl -sS -O http://<Nagios LS IP address>/nagioslogserver/scripts/setup-linux.sh

This command downloads the setup-linux.sh script from the Nagios Log Server URL and ensures it retains its original filename. Since the -sS flags suppress normal output, you won’t see anything unless there’s an error. If the download completes without issues, you can proceed to the next step by running the script with the following command:

sudo bash setup-linux.sh -s <Nagios LS IP Address> -p 5544

This should give us the following output:

With this it is all set up and should be sending Logs to Nagios Log Server.

Step 2: Verify Logs

Next, we need to verify that the Log Server is successfully receiving logs, and this step is straightforward. All you need to do is enter the IP address of your Debian 10 host where it prompts you to ‘Verify Incoming Logs.’ This will confirm that the logs from your host are being properly sent to and received by the Log Server, ensuring everything is functioning as expected.

As you can see, the message confirms that logs are being received from our new host. This means that all the setup steps have been completed successfully, and Nagios Log Server is now properly receiving logs from the newly added host.

Conclusion

By following these steps, you’ve successfully set up Nagios Log Server on your Debian 10 system, allowing you to capture and analyze logs efficiently. The process of configuring your server, running the necessary commands, and verifying log reception ensures that Nagios LS is fully operational, giving you the tools to monitor and manage your system’s health and security.

Now that your log monitoring is set up, you may want to explore additional monitoring methods for a more comprehensive approach. For system performance and resource monitoring, consider setting up NCPA on Debian 10, a flexible agent that integrates seamlessly with Nagios XI. Alternatively, you can also use SNMP on Debian 10 for monitoring with Nagios XI.

Method 1, Step 1: Installing via the Repository (Recommended)

The preferred method for installing NCPA is through the repository. This approach involves a series of simple steps that can all be executed from the command line.

Add the Nagios repository to your sources list: To do this, execute the following command:

echo "deb https://repo.nagios.com/deb/$(lsb_release -cs) /" > /etc/apt/sources.list.d/nagios.list

This command will add the repository to your system, ensuring you have access to the NCPA package.

Add the GPG key for the repository: The GPG key is required to verify the integrity of the packages you’ll download. You might encounter a warning saying that the command used is deprecated, but don’t worry—it will still function correctly. To add the GPG key, use:

wget -qO - https://repo.nagios.com/GPG-KEY-NAGIOS-V3 | apt-key add -

If successful, you should see the message OK, confirming the key was added correctly.

Update your package list: Now that the repository and key are set up, update your package lists:

apt-get update

Install the NCPA package: With the update complete, you can now install NCPA using the following command:

apt-get install ncpa

Step 2: Configure NCPA

After installing NCPA, the agent will work out of the box, but it’s highly recommended to configure the API token for added security. Without this step, the default token will be used, which might not be ideal for your environment. Enter the following into your command line:

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

In the configuration file, look for the line that reads: community_string = mytoken.

Replace mytoken with a secure token of your choice. After updating the token, press CTRL + X, then press Y to confirm the changes, and hit Enter to save the file. We want to use the token we made so there is one final step, which is to restart our NCPA. At the moment its API token that will be accepted is still the default token. We want it to use the newly created one. To do this we enter the following command:

systemctl restart ncpa

This will restart the service, and NCPA will now use the newly configured token.

Step 3: Configuring Firewall

If you’re running a firewall on your system, you’ll need to allow traffic on port 5693, which is used by NCPA. For Ubuntu systems with UFW (Uncomplicated Firewall) enabled, follow these steps to configure the firewall and allow NCPA traffic:

Create the directory for UFW application profiles: First, create the necessary directory where UFW can store application profiles:

sudo mkdir -p /etc/ufw/applications.d

Create a custom application profile for NCPA: Next, set up a custom profile for NCPA by running the following commands:

sudo sh -c "echo '[NCPA]' > /etc/ufw/applications.d/ncpa"
sudo sh -c "echo 'title=Nagios Cross Platform Agent' >> /etc/ufw/applications.d/ncpa"
sudo sh -c "echo 'description=Nagios Monitoring Agent' >> /etc/ufw/applications.d/ncpa"
sudo sh -c "echo 'ports=5693/tcp' >> /etc/ufw/applications.d/ncpa"

Allow NCPA traffic through the firewall: Once the profile is set up, allow NCPA through the firewall with:

sudo ufw allow NCPA

Reload the firewall to apply the changes: Finally, reload UFW to apply the changes:

sudo ufw reload

Step 4 (Optional): Confirm NCPA installation

This step is straightforward. Simply open a web browser and navigate to https://<host-ip-address>:5693.

This will bring you to the login page, where you can enter your token. The purpose of this step is to verify that the NCPA is up and running, that it is reading the token correctly, and that remote access is functional.

Step 5: Configuring on Nagios XI

The final step involves configuring Nagios XI. To do this, navigate to the Configuration Wizards section in Nagios and select the NCPA Wizard.

1. Navigate to the Configuration Wizards section in Nagios XI and select the NCPA Wizard.
2. Enter the necessary information, including the IP address, the token, and the system type (Ubuntu in this case).
3. During the setup, you will be prompted to choose a name for your host and select the services you want to monitor with NCPA.

Once the setup is complete, the new host will appear in your monitoring dashboard. You can navigate to the Host Status section to confirm that it is being monitored properly.

Conclusion

By following this guide, you have successfully installed and configured the Nagios Cross-Platform Agent (NCPA) on Debian 10. You are now able to monitor the system using Nagios XI. If any issues are encountered, we recommend using the Nagios Support Forum.

Prerequisites

• A working instance of Nagios XI
• A internet connection

Step 1: Install SNMP and SNMPD

Most Debian systems don’t come with any of the SNMP tools installed by default, so we will start by installing the necessary tools. We will be starting by updating our package lists using the following command:

sudo apt update

Now we will want to install the SNMP Daemon (snmpd). This is the set of tools responsible for allowing SNMP enabled tools to grab data from the system. We will also be installing snmp for various command line tools, mainly snmpwalk for testing purposes. We will install this by using the command:

sudo apt install snmpd snmp

Step 2: Configure SNMP

Currently the only SNMP requests that the host will respond to will come from the local host. While this is can be useful for testing configuration, we want this to be accessible to Nagios XI. To do this we need to edit snmpd.conf, we will do this with the command:

sudo nano /etc/snmp/snmpd.conf

We are looking for a few sections in this file, first is the agentAddress. The file comes with a commented-out section that allows any IP address to be used, its also possible to change it to the IP address of your Nagios XI instance, however both will work for our purposes. The below image shows it after the change.

This makes the system accessible through SNMP, but we can get no information as it is, now we need to edit the views.

These SNMP view definitions specify which parts of the MIB tree are accessible to users. The first line grants access to standard system-related information (under .1.3.6.1.2.1), while the second allows access to enterprise-specific objects (under .1.3.6.1.4.1), thereby controlling the visibility of SNMP data for monitoring and management purposes. Now we have one last thing to configure is the rocommunity line. This will act as a password for SNMP clients to retrieve data. We will be using the default string ‘public’ for simplicity, but we recommend choosing a more secure word of your choice.

Step 3: Restart the Service

The next step is to restart the SNMP service so that the changes take effect. To do this, simply run the following command:

sudo service snmpd restart

This will restart the SNMP service, and you shouldn’t receive any output if everything is configured correctly. If you do get output, it likely indicates an error in the snmpd.conf file—most often a typo in one of the lines. Please review the file and check for any mistakes. Once that’s sorted, we’ll want to verify that our configurations are working. To do this, we can use the snmpwalk command locally. Alternatively, if you have access to the Nagios XI Linux host, you can perform the test from there as well. The command to use is:

snmpwalk -v 2c -c <rocommunity> localhost/<ip address>

You should receive a very long output, whether you’re testing locally or through the Nagios XI Linux host. If this happens, it confirms that SNMP is set up correctly. It’s even better if you’re able to get it working through the Nagios XI Linux host, as this will verify that the system is correctly receiving and processing SNMP data for monitoring.

Step 4: Set up on Nagios XI

With everything set up, we can now configure monitoring through Nagios XI using the Linux SNMP Wizard. You’ll need to enter the IP address of your Ubuntu device along with the rocommunity string. The SNMP daemon supports multiple versions of SNMP, so the default settings for both the SNMP version and port should work perfectly.

After configuring the settings, you can choose the hostname and select any services you want to monitor through SNMP. Once these steps are completed, your host will be set up for monitoring. By clicking on the hostname, you’ll see that it is being actively monitored and collecting data for the selected services.

Conclusion

With these steps, we’ve successfully set up Debian 10 to be monitored using SNMP with Nagios XI. If you encounter any issues, please refer to the Nagios Support Forum for assistance.