Xt error: Can't open display, if using default DISPLAY

Question

Overview

I\'m attempting to get XQuartz to work on OSX so I can do X11 forwarding via Docker. I\'m following the instructions here. I believe my question may be answer

Answer 1

Dockerized UI Apps in Docker for Desktop MacOS 2018+

Went through all the pain to get the simplest version possible that does not depend on checking port, ip, etc... Here it is.

• Running version XQuartz 2.7.11 (xorg-server 1.18.4)
• Docker version docker version 18.06.1-ce

Make sure to install XQuartz

$ brew install socat
$ brew cask reinstall xquartz

• Don't forget to close logout and log back in.

1. Close any 6000

On a new terminal, verify if there's anything running on port 6000

$ lsof -i TCP:6000
$

If there is anything, just kill the process

2. Close any 6000

Open a socket on that port and keep the terminal open

$ socat TCP-LISTEN:6000,reuseaddr,fork UNIX-CLIENT:\"$DISPLAY\"

3. Verify 6000 is open

In a new terminal, verify if it is opened

$ lsof -i TCP:6000
COMMAND   PID     USER   FD   TYPE             DEVICE SIZE/OFF NODE NAME
socat   29298 mdesales    5u  IPv4 0xe21e43ca9d99bf1d      0t0  TCP *:6000 (LISTEN)

4. Build and Run simple UI App

$ cat Dockerfile.eyes
FROM centos
RUN yum install -y xeyes
CMD ["/usr/bin/xeyes"]
$ docker build -t eyes -f Dockerfile.eyes .

The magic happens using the variables from Docker. Just using the -e DISPLAY=docker.for.mac.host.internal:0 did the trick, as it it will point to the internal IP address and provide that to the docker image. The port forward will do its magic.

$ docker run -e DISPLAY=docker.for.mac.host.internal:0 eyes

I noticed that at this point XQuartz is opened on it own to the same port

$ lsof -i TCP:6000
COMMAND   PID     USER   FD   TYPE             DEVICE SIZE/OFF NODE NAME
socat   29298 mdesales    5u  IPv4 0xe21e43ca9d99bf1d      0t0  TCP *:6000 (LISTEN)
X11.bin 29462 mdesales    8u  IPv6 0xe21e43ca7cdb1135      0t0  TCP *:6000 (LISTEN)

5. Profit and run more apps

$ docker run -e DISPLAY=docker.for.mac.host.internal:0 jess/tor-browser

$ docker run -e DISPLAY=docker.for.mac.host.internal:0 batmat/docker-eclipse