They only provide a Dockerfile because it's so convoluted and patched together that it would be impossible to create a decent guide on how to make this stuff work without revealing just how much it's all held together by duct tape. Still, taking a peek at the Dockerfile will clearly reveal the chaos at play.
Everything runs in separate containers, as it should, and they have automatic restarts, as they should. But then they're so tightly bound together with, you guessed it, duct tape, that when one of them fails, the container just restarts automatically, leaving the user wondering why everything failed, with only a cryptic error message.
The main container is controlled by Supervisor - which is necessary because everything crashes very often, but the end user doesn't notice because Supervisor restarts the services. To outsiders, everything works fine (but occasionally throws some errors).
In short, the current trend is to sweep the dirt under the rug. A trendy rug, though!