For now, it is impossible to let the user check the output of their graphical project. There are wonderful docker images on GitHub and Docker Hub that enable users to access the graphical interface of the application in container. - [jlesage/docker-firefox](https://github.com/jlesage/docker-firefox) which enables users to access GUI via VNC. - [jlesage/docker-baseimage-gui](https://github.com/jlesage/docker-baseimage-gui) which is the base docker image for docker-firefox docker image.