X11 in docker on macOS

x11_docker_mac.md

To forward X11 from inside a docker container to a host running macOS

1. Install XQuartz: https://www.xquartz.org/
2. Launch XQuartz. Under the XQuartz menu, select Preferences
3. Go to the security tab and ensure "Allow connections from network clients" is checked.
4. Run xhost + ${hostname} to allow connections to the macOS host *
5. Setup a HOSTNAME env var export HOSTNAME=`hostname`*
6. Add the following to your docker-compose:

  environment:
  - DISPLAY=${HOSTNAME}:0
  volumes:
  - /tmp/.X11-unix:/tmp/.X11-unix

_{* It should be noted that steps 4 and 5 can be automated to run everytime XQuartz starts, but that's outside of the scope of this gist}

Lot of comments here, not always correct. Here is the TL;DR.

Volume?

  volumes:
  - /tmp/.X11-unix:/tmp/.X11-unix

This is useless, Docker Desktop does not support Unix socket (exception made for a very specific SSH case). A very good reading to get all the details https://briefcase.readthedocs.io/en/stable/how-to/internal/x11passthrough.html

The only solution is to use the network via the DISPLAY=host.docker.internal:0.

libGL error?

If you get the following error:

libGL error: failed to load driver: swrast

You can try to indirect rendering by setting the export LIBGL_ALWAYS_INDIRECT=1

X request error?

If you get the following error:

X Error of failed request:  BadValue (integer parameter out of range for operation)
  Major opcode of failed request:  149 (GLX)
  Minor opcode of failed request:  24 (X_GLXCreateNewContext)
  Value in failed request:  0x0
  Serial number of failed request:  25
  Current serial number in output stream:  26

The latest Quartz version are buggy. I downgraded to 2.7.8 and everything works fine.

X connection error?

If you get Error: Can't open display: host.docker.internal:0, try to ping host.docker.internal. If it works, then the network is up and running but somehow Quartz is not listening/accepting the connection. Otherwise, this is a docker network issue. In the former case, you need to make sure the settings in Quartz are configured properly "allow connection + disable authorisation". Make sure to add in xhost and also try to reboot (sometimes, running/killing quartz to many times makes it unable to listen correctly on the port).

In addition, starting/stopping XQuartz multiple times, it might have changed the port number. Run the command sudo lsof -i -P | grep LISTEN | grep :$PORT and make sure you see x11.bin using port 6000. If it uses something else, for example 6001, it means you need to adapt the DISPLAY to DISPLAY=host.docker.internal:1, if it is 6005 you should set to DISPLAY=host.docker.internal:5.

a better guide that works for me: https://gist.github.com/sorny/969fe55d85c9b0035b0109a31cbcb088

I was stuck on this for a while. Eventually I realized there might be a problem with Xquartz. Indeed after downgrading as suggested by @R1kk3r and following these steps below everything worked fine.

defaults write org.macosforge.xquartz.X11 nolisten_tcp -bool false
export DISPLAY=localhost:0
xhost +localhost
xhost +$(hostname)

Hope that helps.

See here for much easier instructions: https://gist.github.com/devnoname120/ce02ef43da968e15340427c2f1c286a7