nova/HACKING.rst

Nova Style Commandments

• Step 1: Read the OpenStack Style Commandments http://docs.openstack.org/developer/hacking/
• Step 2: Read on

Nova Specific Commandments

• nova.db imports are not allowed in nova/virt/*
• [N309] no db session in public API methods (disabled) This enforces a guideline defined in nova.openstack.common.db.sqlalchemy.session
• [N310] timeutils.utcnow() wrapper must be used instead of direct calls to datetime.datetime.utcnow() to make it easy to override its return value in tests
• [N311] importing code from other virt drivers forbidden Code that needs to be shared between virt drivers should be moved into a common module
• [N312] using config vars from other virt drivers forbidden Config parameters that need to be shared between virt drivers should be moved into a common module
• [N313] capitalize help string Config parameter help strings should have a capitalized first letter
• [N314] vim configuration should not be kept in source files.
• [N315] We do not use @authors tags in source files. We have git to track authorship.
• [N316] Change assertTrue(isinstance(A, B)) by optimal assert like assertIsInstance(A, B).
• [N317] Change assertEqual(type(A), B) by optimal assert like assertIsInstance(A, B)
• [N318] Change assertEqual(A, None) or assertEqual(None, A) by optimal assert like assertIsNone(A)
• [N319] Validate that debug level logs are not translated.
• [N320] Setting CONF.* attributes directly in tests is forbidden. Use self.flags(option=value) instead.
• [N321] Validate that LOG messages, except debug ones, have translations
• [N322] Method's default argument shouldn't be mutable
• [N323] Ensure that the _() function is explicitly imported to ensure proper translations.
• [N324] Ensure that jsonutils.%(fun)s must be used instead of json.%(fun)s

Creating Unit Tests

For every new feature, unit tests should be created that both test and (implicitly) document the usage of said feature. If submitting a patch for a bug that had no unit test, a new passing unit test should be added. If a submitted bug fix does have a unit test, be sure to add a new one that fails without the patch and passes with the patch.

For more information on creating unit tests and utilizing the testing infrastructure in OpenStack Nova, please read nova/tests/README.rst.

Running Tests

The testing system is based on a combination of tox and testr. The canonical approach to running tests is to simply run the command tox. This will create virtual environments, populate them with dependencies and run all of the tests that OpenStack CI systems run. Behind the scenes, tox is running testr run --parallel, but is set up such that you can supply any additional testr arguments that are needed to tox. For example, you can run: tox -- --analyze-isolation to cause tox to tell testr to add --analyze-isolation to its argument list.

Python packages may also have dependencies that are outside of tox's ability to install. Please refer to doc/source/devref/development.environment.rst for a list of those packages on Ubuntu, Fedora and Mac OS X.

It is also possible to run the tests inside of a virtual environment you have created, or it is possible that you have all of the dependencies installed locally already. In this case, you can interact with the testr command directly. Running testr run will run the entire test suite. testr run --parallel will run it in parallel (this is the default incantation tox uses.) More information about testr can be found at: http://wiki.openstack.org/testr

Building Docs

Normal Sphinx docs can be built via the setuptools build_sphinx command. To do this via tox, simply run tox -evenv -- python setup.py build_sphinx, which will cause a virtualenv with all of the needed dependencies to be created and then inside of the virtualenv, the docs will be created and put into doc/build/html.

If you'd like a PDF of the documentation, you'll need LaTeX installed, and additionally some fonts. On Ubuntu systems, you can get what you need with:

apt-get install texlive-latex-recommended texlive-latex-extra texlive-fonts-recommended

Then run build_sphinx_latex, change to the build dir and run make. Like so:

tox -evenv -- python setup.py build_sphinx_latex
cd build/sphinx/latex
make

You should wind up with a PDF - Nova.pdf.