The topic of monitoring happens to be something I hold very close to my heart. I spent years watching many organizations’ websites and applications to ensure that their availability holds as close as possible to 99.99% uptime. This task was not for the meek of heart in any realm of things. The thing that got me through it all was having a solid method to monitoring the environments that did not require me to literally watch it every second of the day. In this chapter, we will step through some of the common approaches to checking the health of your OpenStack cloud manually and then leverage Ansible to set up my favorite open source monitoring tool, Nagios.