If you're looking for a way to run apps with GUI inside a docker container, on MacOS/OSX, here's one way of doing it.

https://medium.com/@cristiterpea/running-docker-gui-apps-on-osx-the-safer-way-8bbdbea2241c

In previous existing solutions, you were either required:

• to bind to *:6000 (by enabling XQuartz "Allow connections from network clients" option) - opening to potential remote attacks.
• to ssh to the docker container

It appears that a docker container can connect to its host, through lo0 interface - by adding an alias.

Used socat for forwarding /tmp/.X11-unix/X0 to a socket bound to port 6000 of a lo0 alias.

$ socat TCP-LISTEN:6000,reuseaddr,fork,bind=$ip UNIX-CLIENT:\"$SOCKET_FILE\" &
$ netstat -an | grep LISTEN
tcp4       0      0  10.254.254.254.6000    *.*                    LISTEN

• XQuartz: https://www.xquartz.org
• socat: brew install socat
• Docker
• Add persistent lo0 alias: https://gist.github.com/ralphschindler/535dc5916ccbd06f53c1b0ee5a868c93 (or add a temporary alias, for testing: sudo ifconfig lo0 alias 10.254.254.254/24)

docker build -t firefox .
./run.sh

• MacOS Sierra 10.12.3
• Docker 1.13.1 (15353)
• XQuartz 2.7.11 (xorg-server 1.18.4)

Read run.sh and docker_osx_display_funcs.sh

To Swen for the lo0 idea. (https://github.com/Photonios/qt-meetup-demo/blob/master/run.sh)