There are several different use cases covered in this KB article: The sections below provide examples of how to perform these checks using different methods. Nagios vs Zabbix - What's the Difference ? (Pros and Cons) Can I tell police to wait and call a lawyer when served with a search warrant? The host or the services will be tested again and again till the time the status is permanent. An external application checks the status on hosts/services and writes the result to External Command File. Here is another example to check CPU: nagios will indicate warning if the % cpu utilized by any process is greater than 70% and will indicate critical alert if the % cpu is greater that 80% This will give an idea on whether the execution will be successful and what the output of the script will look like. I don't know if it's best practice or not , but i would declare count Warnings as an integer variable when doing arithmetic operations. You can create a host file inside the server directory of Nagios and mention the host and service definitions. Nagios check_dns / check_ip Example - Nagios Exchange This tutorial will cover the process of using some of these scripts for checking common services, such as MySQL, Apache web server, DNS, etc. The following is a sample script that will accept the host name, status code, and output from a check and will submit these to Nagios: As an example of the use of this script, the command that is sent to Nagios for host01, status code 2 (UNREACHABLE) and output router 192.168.1.2 down would be as follows: When submitting results, it is worth noting that Nagios might take some time to process them, depending on the intervals between Nagios checks of the external command pipe. Code-GPT is an extension for VS Code that provides you instant explanations for your code within the code editor using AI. To use a custom script as a plugin to run remotely through NRPE, you should first write the script on the server, for instance in /usr/local/scripts/check_root_home_du.sh: The previous script is a very simple example, checking the disk usage of the directory /root and setting a threshold for considering it OK, Warning or Critical. Nagios Tutorial for Beginners - TAE - Tutorial And Example This tutorial was tested using Nagios Core 4.3.4 on Debian 9.2if(typeof ez_ad_units!='undefined'){ez_ad_units.push([[300,250],'howtoforge_com-box-3','ezslot_3',106,'0','0'])};__ez_fad_position('div-gpt-ad-howtoforge_com-box-3-0'); Even though Nagios Exchange has thousands of available plugins to freely download, sometimes the status needed to be checked is very specific for your scenario.