> For the complete documentation index, see [llms.txt](https://indigo-dc.gitbook.io/opie/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://indigo-dc.gitbook.io/opie/contributing.md).

# Developer guide

## opie Style Commandments

opie follows the same style Commandments as upstream OpenStack Nova, so the following reference pacge must be kept under the pillow:

<http://docs.openstack.org/developer/hacking/>

## How to contribute

If you would like to contribute to the opie development, first check the existing [blueprint](https://blueprints.launchpad.net/openstack/?searchtext=preemptible-instances) and the corresponding [spec](https://review.openstack.org/#/c/104883/).

All contributions are welcome through pull requests against:

<https://github.com/indigo-dc/opie>

Bugs should be filled in Github:

<https://github.com/indigo-dc/opie/issues>

## Testing

### 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.

### 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.

To run a single or restricted set of tests, pass a regex that matches the class name containing the tests as an extra `tox` argument; e.g. `tox -- OpieFilterSchedulerTestCase` (note the double-hypen) will test all the Filter Scheduler tests from `opie/tests/test_scheduler.py`; `-- OpieFilterSchedulerTestCase.test_detect_preemptible_empty` would run just that test, and `-- OpieFilterSchedulerTestCase|PreemptibleCountWeigherTestCase` would run tests from both classes.

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>

## Docs

Normal Sphinx docs can be built via the setuptools `build_sphinx` command. To do this via `tox`, simply run `tox -e docs`, 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.