title: Use docker-compose with multiple repositories
body: <p>I'm currently struggling with the deployment of my services and I wanted to ask, what's the proper way when you have to deal with multiple repositories. The repositories are independent, but to run in production, everything needs to be launched.</p>
  
  <p>My Setup:</p>
  
  <ul>
  <li>Git Repository Backend:
  
  <ul>
  <li>Backend Project Rails</li>
  <li>docker-compose: backend(expose 3000), db and redis</li>
  </ul></li>
  <li>Git Repository Frontend
  
  <ul>
  <li>Express.js server</li>
  <li>docker-compose: (expose 4200)</li>
  </ul></li>
  </ul>
  
  <p>Both can be run independently and test can be executed by CI</p>
  
  <ul>
  <li>Git Repository Nginx for Production
  
  <ul>
  <li>Needs to connect to the other two services (same docker network)</li>
  <li>forwards requests to the right service</li>
  </ul></li>
  </ul>
  
  <p>I have already tried to include the two services as submodules into the Nginx repository and use the docker-compose of the nginx repo, but I'm not really happy with it.  </p>