When Packstack installed OpenStack in Chapter 2, RDO Installation, one of the options that's available is to install and configure Nagios. If you remember, this was one of the options that was set to yes in our installation:

CONFIG_NAGIOS_INSTALL=y

Since Packstack did the base Nagios installation for us, we are not going to cover the details of a fresh Nagios installation. There are plenty of resources available on the Internet that you can search for if you want more information on doing a fresh Nagios installation outside of Packstack.

In the following sections, we'll add configurations to Nagios configuration files. To apply configuration changes, the service will need to be restarted for Nagios to read the updates and start checks based on the new configurations. For example purposes, we will refer to a set of monolithic configuration files to configure Nagios in this chapter. Each file that is referred to in this chapter is referred to in the top level Nagios configuration...