Icinga 2 is a popular open source network resource monitoring system, and Icinga Web 2 is a web interface for Icinga 2. This article will describe how to install them on a CentOS 7 server. - A fresh Vultr CentOS 7 server instance. - A [sudo user](https://docs.vultr.com/how-to-use-sudo-on-a-vultr-cloud-server). sudo yum install epel-release -y sudo yum update -y sudo shutdown -r now After the reboot, use the same sudo user to log in. Install Apache using YUM: sudo yum install ......