With the number of moving parts that make up an OpenStack installation, it is inevitable that as the cluster is brought up for the first time, a few things will not work. Further, as the cluster operates, there will also be service failures that should be addressed. It is very important to be able to troubleshoot a running OpenStack installation. Let's take a look at some of the details of how things work under the hood and how to figure out what is going wrong when things are not working properly. We will look at general troubleshooting and then take a look in detail at a few components to help troubleshoot each of them.
Most of the OpenStack command-line commands support passing --debug before a subcommand. For example, with hypervisor or server lists, it could look like this:
$ openstack --debug hypervisor list $ openstack --debug server list
Note that --debug is put before the subcommand being executed. Using the debug option like this is helpful because it will show curl commands for each of the API calls that are being made from the command-line client to the API endpoints. Hosts and ports are included in this, so if your command-line client has trouble connecting to the endpoint, you can use the debug option to get more detail. If you need to see what information is being sent from or returned to the command line, the debug option will show those details.