With all the infrastructure services covered, we can move on to the core OpenStack services. In this section, we will cover a few principles that can be used for any of the OpenStack services. This approach allows you to interchange any of the basic approaches for any service, based on your personal needs.
The first three services that I normally go in and check are Keystone, Nova, and Neutron. These services can have adverse effects on many other services within your cloud and need to be running properly to technically have a functioning cloud. While there is no distinct OpenStack command that you can use to check the Keystone service, it will become very obvious if the Keystone service is not operational, as any/all OpenStack CLI commands will fail. I personally feel that the easiest way to test our Keystone is to either log into the Horizon dashboard or issue the following Keystone CLI command:
$ keystone service-list
If you get the list of services using Keystone...