So I believe there are two separate applications here. You can continue to run the RTFace backend by launching the pre-built docker image. You then want to setup the client somewhere else which will be the camera source. On that machine you can clone the repository, change the config, and then start ./ui.py so that it sends the video stream to the backend which you already have running elsewhere. Conceivably you could have them both on the same machine, running the backend in a container, and using the source repository on the host as the client. Does that make sense?