There is an extensive collection of logs across an OpenStack cluster, and they are your best friend. Often a good place to start is when an API call succeeds, but the end result is, not as you expect, to tail the log files of a component that you're having trouble with. You can do this as, or right after, you execute the command that you are seeing failure with. For example, if you are having trouble connecting to Keystone, it might not be running properly or might be throwing errors for some reason. Start a tail on /var/log/keystone/keystone.log and rerun the command that is failing. This is shown in the following command:

$ tail -fn0 /var/log/keystone/keystone.log

In this command, -f indicates that we follow the log or show new entries as they are added. The -n0 means show the most recent zero lines; in other words, any previous content in the file is suppressed so that you only see new entries when you run the command. All of the OpenStack components are going to...