This guide shows how to use Nagios plugins to monitor devices in Verax NMS Express. Verax NMS is a cross-platform network and application monitoring software.
- Sample Nagios plugin for CPU check in a Shell Script format (.sh file) http://exchange.nagios.org/directory/Plugins/System-Metrics/CPU-Usage-and-Load/Check-CPU-LOAD-using-SNMP/details
- Verax NMS Express ver. 1.9.5: http://www.veraxsystems.com/en/products/nms
Adding Nagios Plugin To The Device
First, download a plugin. In this example I will use plugin for checking CPU usage over the SNMP (check_snmp_cpu.sh).
Put plugin in a folder on the same server where Verax NMS Express is installed. In my case it will be:
Note: Make sure that folder containg the plugin has the right file permissions (CHMOD: 777).
Now, let’s add shell script sensor to the device:
- Log into the Verax NMS, select Home from the main menu and select the right device from the aspects tree.
- In Monitors tab select Add option and click Go. The system will display a pop-up dialog with sensors available for your device.
- Select Shell Script Sensor from the sensors tree and click Next.
- Now you have to specify your sensor parameters.
System will ask you to enter the following sensor-specific parameters:
- Host – in most cases, the host address is an IP address of the device.
- Path to script – path to the script file located on the server where Verax NMS Express is installed.
For me it’s:
- Output data format – an output data format which is expected to be returned by the script.
- Ignore – only the return code/time of response is taken into account.
- Nagios format – format of the script output is compatible with Nagios.In this case set out format to “Nagios” which is by default: ‘label’=value[UOM];[warn];[crit];[min];[max]
- Script arguments (not mandatory) – arguments are passed due to the uploaded script. You can use the following placeholders in the arguments:
- %DEVICE_IP% – IP address of the device.
- %SNMP_COMMUNITY% – SNMP community string for the device.
- %TIMEOUT% – Timeout value for the sensor.
- %WARNING_THRESHOLD% – Value for the warning threshold for the sensor.
- %CRITICAL_THRESHOLD% – Value for the critical threshold for the sensor.
- Environment variables (not mandatory) – provide a simple way to share configuration settings between multiple applications and processes in Linux. Each of the variables should be definied as “key=value” and they should be separated by “;”.
- Exit codes greater than this value [warning (exit code 1), error (exit code 2), unknown value (exit code 3)] – it means that if the script’s exit code will be greater than or equal to chosen return code, sensor’s execution will result with error.
- Click Finish to confirm.
- Sensor is now added and will be visible in the Aspects tree.
In order to check if the sensor is working properly, select Execute script and show output option from local actions menu. If everything’s OK system will display pop-up dialog with a script’s response. It should look like this:
If you performed all actions described in this guide Nagios plugin will now monitor your device and its responses will be presented on a performance chart.