One of the common causes for service degradation or interruption is still the failure or exhaustion of your basic infrastructure resources. This post gives you an intro how you can monitor your basic resources with Prometheus. It shows the setup with Ansible and the data visualization with Grafana. The post does not show all the capabilities of Prometheus. In fact, I’m showing you only the simplest configuration. The benefit of this post is, that it takes you from start to finish and gives you a playground you can easily recreate when things go wrong, thanks to Vagrant and VirtualBox. Beware, as this is a non-trivial (non-hello-world) example, this post is really long.