Docker sounds brilliant, but I haven't had much luck with deploying my (moderately complex) Django apps on it. For example, I want the postgres db data to live outside the container, but volumes can't currently do that with Dockerfiles: they're initialized at "docker build" and then the files are just overwritten when trying to mount an external volume.<p>Another use case is trying to spin up a development container (where the code resides on the host), but, again, shared volumes overwrite the directory. You can ADD your code initially and then mount the volume when you run it, but it's added hassle.