Running Chromium inside Docker - Gtk: cannot open display: :0

Try

xhost local:root

This solve mine, I am on Debian Jessie. https://github.com/jfrazelle/dockerfiles/issues/4

i don't know much about chromium, but, I did work with X way back when :-) When you tell an X client to connect to :0, what you are saying is connect to port 6000 (or whatever your X server runs on) + 0, or port 6000 in this case. In fact, DISPLAY is IP:PORT (with the +6000 as mentioned above). The X server is running on your host, so, if you set:

DISPLAY=your_host_ip:0

that might work. However, X servers did not allow connections from just any old client, so, you will need to open up your X server. on your host, run

xhost +

before running the docker container. All of this is assuming you can run chromium on your host (that is, an X server exists on your host).

Adding as reference (see real answer from greg)

In your Linux host add

  xhost +"local:docker@"

In Docker image add

RUN apt-get update
RUN apt-get install -qqy x11-apps

and then run

sudo docker run \
    --rm \ # delete container when bash exits
    -it \ # connect TTY
    --privileged \
    --env DISPLAY=unix$DISPLAY \ # export DISPLAY env variable for X server
    -v $XAUTH:/root/.Xauthority \ # provide authority information to X server
    -v /tmp/.X11-unix:/tmp/.X11-unix \ # mount the X11 socket
    -v /home/alex/coding:/coding \
    alexcpn/nvidia-cuda-grpc:1.0 bash

Inside the container -check a sample command

xclock