Docker with BRIDGE network. for Ubuntu 16.04 with display manager lightdm:
cd /etc/lightdm/lightdm.conf.d
sudo nano user.conf
[Seat:*]
xserver-allow-tcp=true
xserver-command=X -listen tcp
you can use more private permissions
xhost +
docker run --volume="$HOME/.Xauthority:/root/.Xauthority:rw" --env="DISPLAY=$HOST_IP_IN_BRIDGE_NETWORK:0" --net=bridge $container_name