dox

dox is a tool for using docker containers to run local tests, inspired by tox and virtualenv for python. There are two elements to its configuration:

• What commands should be run?
• In what image should they be run?

If there is a dox.yml file, you're set. You want to specify what image to use and what commands to run. You win:

image: ubuntu:trusty
commands: |
  pip install . -r test-requirements.txt
  python setup.py test

You might either not be willing to commit to dox as a way of life yet, or you may want to use dox in a project that similarly has not done so.

What commands should be run

dox.yml wins.

If there is a tox.ini file, the commands specified in the base [testenv] will be used.

If there is a .travis.yml file, the script section will be used.

If there are none of those things, dox will do its best to infer what should be done. Examining the directory can often provide hints if you haven't been too clever. For instance, if you have a Gruntfile, you probably want to run grunt. If you have a Makefile, then make && make test is probably your bag. If you have a Makefile.am, you probably want to run autotools first. If you have a setup.py file, python setup.py test is a likely choice (although in that case, you probably haven't done it right because setuptools support for this is quite awful.)

After all of that, if we still can't figure out what you want - it's probably easiest to just edit a file called dox.yml and put in a section telling us what to do.

In what image should they be run

Again, dox.yml wins, and thanks for making things easy!

If there is a tox.ini file, and it contains a [docker] section, the value in "image" will be used:

[docker]
image=ubuntu:trusty

If there is not an image key in the docker section or an image key in the dox.yml but there is a Dockerfile in the repo, an new image will be built using the Dockerfile and the test commands will be run inside of the image.

If all of that fails, tests are going to run in a bare ubuntu image. Good luck!

Image Caching

Every run actually has two images associated with it: The base image and the test image.

The image referenced above is the base image. When you execute dox, it will search docker for the named image. If it exists, it will do nothing. If it does not, it will either pull it, or, it will build it from the Dockerfile. In the case of building from a Dockerfile, dox will make an image named for the source directory. So if you're in ~/src/openstack/nova, it'll make an image called "dox/nova/base".

The test image is an image made by dox for the test run. Similar to the base run, it'll have a generated name, such as "dox/nova/test", and similar to the base image, it will get generated once and then left alone.

If you want to regenerate the test image, you can run dox with the -r option. If you want to regenerate/repull everything, you can run it with the --rebuild-all option.

The reasoning behind this is that the base image should really be the substrata which doesn't have a lot to do with the repo itself ... it shouldn't really expect to change much based on day to day changes in the repo. The test image on the other hand is built a bit more based on the repo itself. So, for instance, in the base image you might want to do things like:

apt-get install libxml-dev

and in the test image, you'd want things like:

pip install -U requirements.txt

Neither change frequently, but the second it more likely to change day to day than the first.

Additional information

Regardless, dox will mount the current source dir as a volume at /src in the container and will run commands in that context.

dox will attempt to reuse containers. Since the source is bind-mounted into the container, things that might be expensive like copying source dirs or re-installing the source into the system can be minimized.

Advanced

The dox.yml file can reference multiple images, such as if your test suite needs things like a MySQL server. At least, that's the theory. This is not yet implemented.