Before we create a server to run the OpenStack Compute services to run our instances, there are some final services that need be installed on the controller
node where the OpenStack Identity and Image services are running. Separating out controller services from the Compute nodes allows us to scale our OpenStack environment resources horizontally in the controller and Compute services.
To do this, we will install some further packages to our controller
node that we created in Chapter 1, Keystone – OpenStack Identity Service; Chapter 2, Glance – OpenStack Image Service; and Chapter 3, Neutron - OpenStack Networking, currently running Keystone and Glance. The services are as follows: