Tempest supports the REST API with JSON or XML format. It is implemented based on the “unittest2” and “nose” python test frameworks.
You can run Tempest cases like these ways:

1. Run all cases in the specified directory (and sub directories):
   nosetests Tempest
2. Run all cases in the specified file:
   nosetests tempest/tempest/api/compute/flavors/test_flavors.py
3. Run all cases in the specified class:
   nosetests tempest/tempest/api/compute/flavors/test_flavors.py:FlavorsTestJSON
4. Run the specified function:
   nosetests tempest/tempest/api/compute/flavors/test_flavors.py:FlavorsTestJSON.test_list_flavors

Hope it helps.
BTW, Nose recognizes test cases form source files, directories or packages automatically. Any classes, functions, files, directories or sub classes that match the regular expression: (?:^|[b_.-])[Tt]est will be identified and executed.
You can also write your own test cases by following the guide:
http://docs.openstack.org/developer/t...