Docker, Django and Selenium - Selenium unable to connect

Question

I have Docker configured to run Postgres and Django using docker-compose.yml and it is working fine.

The trouble I am having is with Selenium not being able to conne

Answer 1

I've been struggling with this as well, and I finally found a solution that worked for me. You can try something like this:

postgis:
  dockerfile: ./docker/postgis/Dockerfile
  build: .

django:
  dockerfile: ./docker/Dockerfile-dev
  build: .
  command: python /app/project/manage.py test my-app
  volumes:
    - .:/app
  ports:
    - "8000:8000"
  links:
    - postgis
    - selenium  # django can access selenium:4444, selenium can access django:8081-8100
  environment:
    - SELENIUM_HOST=http://selenium:4444/wd/hub
    - DJANGO_LIVE_TEST_SERVER_ADDRESS=django:8081-8100  # this gives selenium the correct address

selenium:
  image: selenium/standalone-firefox-debug
  ports:
    - "5900:5900"

I don't think you need to include port 4444 in the selenium config. That port is exposed by default, and there's no need to map it to the host machine, since the django container can access it directly via its link to the selenium container.

[Edit] I've found you don't need to explicitly expose the 8081 port of the django container either. Also, I used a range of ports for the test server, because if tests are run in parallel, you can get an "Address already in use" error, as discussed here.