GUI interface (xclock) can´t forward X-window

Dear all, I´ve started recently to use Docker and I have a GUI application that I´m trying to export from a remote server to my terminal. However, I can´t X11-forwarding from inside the docker container to my screen and would like your help to solve it.

Briefly, I´m using a laptop with MobaXterm program to connect in an ubuntu remote host that has the docker installed. Once connected, to test the X-window, I can execute the xclock command and the clock open on my screen correctly. At this point the echo $DISPLAY command returns localhost:12.0

So, to open my container and try to execute the xclock command from inside it I do:

$ xhost +
$ xhost +local:docker
$ docker run -it -e DISPLAY=$DISPLAY -v /tmp/.X11-unix:/tmp/.X11-unix ubuntu bash

Now inside the container

apt-get update

apt-get upgrade

apt-get install x11-apps (which give me the xclock program)

but then, when I execute the xclock command I get the following error:


Error: Can’t open display: localhost:12.0

Does anybody have any idea about why the xclock command inside the container do not export the clock on my laptop screen?

Thank´s for your help!