Comment 0 for bug 1212545

One of Tempest's prime function is to ensure that your OpenStack cloud
works with the OpenStack API as documented. The current largest
portion of Tempest code is devoted to test cases that do exactly this.

It's also important to test not only the expected possitive path on
APIs, but also to provide them with invalid data to ensure they fail
in expected and documented ways. Over the course of the OpenStack
project Tempest has discovered many fundamental bugs by doing just
this.

In order for some APIs to return meaniful results, there must be
enough data in the system. This means these tests might start by
spinning up a server, image, etc, then opperating on it.