I’d back up a bit and ask why two humans are sharing one container. Is it for collaboration? Is the distinction between users important? Should they have their own files, etc.? repo2docker creates an image with a single user account that launches a single notebook server. The notebook server is fundamentally a single-user server. Two humans can share this server, even though they will both appear as the same system user in the container. Both folks need only the URL and token and/or password for the container to use it at the same time. If you want multiple separate users with their own accounts, try something like JupyterHub. You can use repo2docker images with JupyterHub, but each user would have their own container.