see: https://medium.com/@gustav0.lewin/how-to-make-a-docker-container-with-vnc-access-f607958141ae
To start the VNC server, it’s necessary to execute the script start-vnc.sh. You can automate this process by specifying an entrypoint in the Dockerfile. However, if you prefer manual execution like me: docker exec -ti vnc_ubuntu /bin/bash
Once you have access to the container’s CLI:
./start-vnc.sh
Now you can use a VNC client in the host machine to access your container via localhost:5901 (tested with RealVNC Viewer). The password was defined in the Dockerfile as “password”.