Nova contains a suite of unit tests, in the nova/tests directory.
Any proposed code change will be automatically rejected by the OpenStack Jenkins server  if the change causes unit test failures.
Run the unit tests by doing:
The run_tests.sh script supports several flags. You can view a list of flags by doing:
This will show the following help information:
Usage: ./run_tests.sh [OPTION]... Run Nova's test suite(s) -V, --virtual-env Always use virtualenv. Install automatically if not present -N, --no-virtual-env Don't use virtualenv. Run tests in local environment -s, --no-site-packages Isolate the virtualenv from the global Python environment -r, --recreate-db Recreate the test database (deprecated, as this is now the default). -n, --no-recreate-db Don't recreate the test database. -x, --stop Stop running tests after the first error or failure. -f, --force Force a clean re-build of the virtual environment. Useful when dependencies have been added. -p, --pep8 Just run pep8 -P, --no-pep8 Don't run pep8 -c, --coverage Generate coverage report -h, --help Print this usage message --hide-elapsed Don't print the elapsed time for each test along with slow test list
Because run_tests.sh is a wrapper around nose, it also accepts the same flags as nosetests. See the nose options documentation for details about these additional flags.
Instead of running all tests, you can specify an individual directory, file, class, or method that contains test code.
To run the tests in the nova/tests/scheduler directory:
To run the tests in the nova/tests/test_libvirt.py file:
To run the tests in the HostStateTestCase class in nova/tests/test_libvirt.py:
To run the ToPrimitiveTestCase.test_dict test method in nova/tests/test_utils.py:
By default, when one or more unit test fails, all of the data sent to the logger during the failed tests will appear on standard output, which typically consists of many lines of texts. The logging output can make it difficult to identify which specific tests have failed, unless your terminal has a large scrollback buffer or you have redirected output to a file.
You can suppress the logging output by calling run_tests.sh with the nose flag:
By default, the tests use the Python packages installed inside a virtualenv . (This is equivalent to using the -V, --virtualenv flag). If the virtualenv does not exist, it will be created the first time the tests are run.
If you wish to recreate the virtualenv, call run_tests.sh with the flag:
Recreating the virtualenv is useful if the package dependencies have changed since the virtualenv was last created. If the tools/pip-requires or tools/install_venv.py files have changed, it’s a good idea to recreate the virtualenv.
By default, the unit tests will see both the packages in the virtualenv and the packages that have been installed in the Python global environment. In some cases, the packages in the Python global environment may cause a conflict with the packages in the virtualenv. If this occurs, you can isolate the virtualenv from the global environment by using the flag:
-s, --no-site packages
If you do not wish to use a virtualenv at all, use the flag:
Some of the unit tests make queries against an sqlite database . By default, the test database (tests.sqlite) is deleted and recreated each time run_tests.sh is invoked (This is equivalent to using the -r, --recreate-db flag). To reduce testing time if a database already exists it can be reused by using the flag:
Reusing an existing database may cause tests to fail if the schema has changed. If any files in the nova/db/sqlalchemy have changed, it’s a good idea to recreate the test database.
Running Tests from Shared Folders
If you are running the unit tests from a shared folder, you may see tests start to fail or stop completely as a result of Python lockfile issues . You can get around this by manually setting or updating the following line in nova/tests/fake_flags.py:
Note that you may use any location (not just /tmp!) as long as it is not a shared folder.
|||See Continuous Integration with Jenkins.|
|||See Setting Up a Development Environment for more details about the use of virtualenv.|
|||There is an effort underway to use a fake DB implementation for the unit tests. See https://lists.launchpad.net/openstack/msg05604.html|
|||See Vish’s comment in this bug report: https://bugs.launchpad.net/nova/+bug/882933|