GUI, webcam and GPU passthrough for ROS 2 and MuJoCo containers
Containers are headless by design. This project needs two windows, a webcam and a GPU — so the Compose file spends most of its lines punching carefully chosen holes back through the isolation. Two containers, two windows, one X display: the Qt/OpenCV tracker (vision_tracker) and the GLFW MuJoCo viewer (mujoco_twin), recorded on Wayland through XWayland. Windows: pass the X11 socket through # environment: DISPLAY: ${DISPLAY:-:0} QT_X11_NO_MITSHM: 1 volumes: - /tmp/.X11-unix:/tmp/.X11-unix:rw Piece What it does /tmp/.X11-unix mount the X server listens on a Unix socket here (X0 for :0); mounting it gives the container a line to it DISPLAY tells X clients (GLFW, Qt) which display to use; defaults to :0 QT_X11_NO_MITSHM=1 stops Qt — OpenCV’s imshow backend — from using MIT-SHM, which fails across containers and gives blank or garbled windows xhost +local:root (in setup_host.sh) the X server refuses untrusted clients; this admits local root, which is who the containers run as On Wayland # Wayland sessions (KDE Plasma, GNOME) still run XWayland on :0, and both windows open through it — the recording above was made exactly that way. Running MuJoCo natively on a Wayland host, GLFW may warn Wayland: The platform does not provide the window position; it’s harmless.