Setting up Nagios as a monitoring server

For this chapter, we are going to work with Nagios as our best choice, considering the performance and the simplicity of its setup and configuration. As we have already mentioned, Nagios is open source software that can be installed on multiple Linux distributions. In our case, we will be installing it on CentOS 7. It is a network, infrastructure, and server-monitoring tool. It will be monitoring switches, applications, and services. It has an alerting feature that helps inform users about all issues that occur while the infrastructure is being monitored. It also alerts the user if the issues have been fixed. Other than monitoring, Nagios also has the ability to identify system or network issues that could cause problems, with real-time problem notification. Furthermore, it has some security features, by virtue of which it can identify security breaches in the infrastructure.

In this section, we are going to install Nagios on a machine. It will act...