X11 forwarding of a GUI app running in docker

Question

First off: I have read the answers to similar questions on SO, but none of them worked.

The situation:

• App with GUI is running in a docker container (C

Answer 1

Thanks so much @Lazarus535
I found that for me adding the following to my docker command worked:
--volume="$HOME/.Xauthority:/root/.Xauthority:rw"
I found this trick here
EDIT:
As Lazarus pointed out correctly you also have to set the --net=host option to make this work.