Using Travis CI for testing Django projects

A couple of weeks months1 ago in my post about using tox with Django projects, I mentioned using Travis CI as well as tox for testing.

There’s plenty of documentation out there for Python modules and Django applications, but not so much guidance for testing a complete Django project. I can only speculate that this is because testing projects normally involves more moving parts (e.g., databases) as opposed to applications which are supposed to be self-contained.

A good example here is the cookiecutter templates of Daniel Greenfeld – one of the authors of Two Scoops of Django. His djangopackage template contains a .travis.yml file, yet his django[project] template doesn’t. Since many consider these templates best practices, and Two Scoops as a Django “bible”, perhaps I’m wrong to want to use CI on a Django project?

Well (naturally) I don’t think I am, so here is how to do it.

Travis CI has a whole bunch of services you can use in your tests. The obvious ones are there e.g., PostgreSQL, MySQL, and Memcached. For a more complete system, there’s also Redis, RabbitMQ, and ElasticSearch. Using these you can build a pretty complete set of integration tests using the same components you will in a production environment.

For the purposes of testing capomastro2, we only need a PostgreSQL database 3. The first step is to say we want PostgreSQL available during tests:

services:
– postgresql

Now we need to create the database, using the postgres user provided by Travis CI:

  psql -c 'create database capomastro;' -U postgres

The next part is to configure our Django project to use this database. Fortunately our project already provides a sample local_settings.py that is configured for connecting to PostgreSQL on localhost without a password, so all we need to do is modify this file to use the same postgres user:

  cp capomastro/local_settings.py.example capomastro/local_settings.py
  sed -i -e 's/getpass.getuser()/"postgres"/g' capomastro/local_settings.py

Finally we can call the Django syncdb (and migrate because like everyone else, we use South) to setup our database:

  python manage.py syncdb --migrate --noinput

All of this is done in the before_script hook in Travis CI:

before_script:
– cp capomastro/local_settings.py.example capomastro/local_settings.py
– psql -c 'create database capomastro;' -U postgres
– sed -i -e 's/getpass.getuser()/"postgres"/g' capomastro/local_settings.py
– python manage.py syncdb –migrate –noinput

We can now execute the full test suite for the project, using the same database we use in development and production!

For reference, here is the complete .travis.yml file:

language: python
services:
– postgresql
python:
– 2.7
install:
– pip install -r dev-requirements.txt
before_script:
– cp capomastro/local_settings.py.example capomastro/local_settings.py
– psql -c 'create database capomastro;' -U postgres
– sed -i -e 's/getpass.getuser()/"postgres"/g' capomastro/local_settings.py
– python manage.py syncdb –migrate –noinput
script:
– python manage.py test


  1. Wow, this post has been sitting in drafts for quite a while! 
  2. master builder“ 
  3. A lot of people deploy against PostgreSQL, but develop and test against SQLite for speed and convenience. This will eventually bite them.