Dockerfile directive

I was trying to use rancher to manage my multi-service applications, since I was quite new to the system I was struggling trying to understand why I could not get anything right.
Then I have found this bug and all become clear, all my efforts to get a stack up and running were wasted because the dockerfile directive is ignored.
This seems to me a very important piece of the puzzle and I cannot understand how and why this is not treated as a serious bug.
Maybe I am missing something and somebody can suggest me a different approach on what I am trying to do:

  1. get a postgresl service
  2. Run a Django app with uwsgi
  3. Expose it via nginx
    Maybe somebody can show me how I can do this without different Dockerfile instances.

You can try building your containers on your computer (or a build server like Jenkins) and push them to DockerHub or your own private registry. Then in your docker-compose, you just specify the image name and Rancher will pull the image.

Thank you for the advise, I will try that, yet I hope the bug can be fixed soon.