Running firefox in a ubuntu docker container on localhost: Unable to init server: Broadway display type not supported:

Question

I am experimenting with running X11 GUI programs from a docker container on localhost:

FROM ubuntu:20.04
RUN apt-get update && apt-get install -y firefox
ARG home=/root
WORKDIR $home
COPY entrypoint.sh .
ENTRYPOINT ["./entrypoint.sh"] 

where the entrypont.sh file is:

#! /bin/bash
firefox &
exec bash

Building the image with:

docker build -t firefox-ubuntu-2004 . 

And running the container (localhost: Ubuntu 20.04):

XSOCK=/tmp/.X11-unix
XAUTH=/tmp/.docker.xauth
DISPLAY="localhost:0"
xauth nlist $DISPLAY | sed -e 's/^..../ffff/' | xauth -f $XAUTH nmerge -
docker run -it --rm \
       -e DISPLAY=$DISPLAY \
       -v $XAUTH:$XAUTH \
       -v $XSOCK:$XSOCK \
       -e XAUTHORITY=$XAUTH \
       firefox-ubuntu-2004

The output error message from running the last command is:

Unable to init server: Broadway display type not supported: localhost:0
Error: cannot open display: localhost:0

Answer 1

The --net=host in the docker command should do the job

docker run --name myContainer -it --net=host  fromMyimage:latest

along with using host.docker.internal instead of localhost for connecting to the docker's host on OSX.