Major changes to the VNC generator (generators/middleware.py):
1. Replace Xtigervnc + vncserver wrapper with xvfb + x11vnc.
- Xtigervnc defaults to daemon mode (no -fg flag exists), so systemd
Type=simple couldn't track it; x11vnc attaches to Xvfb in
foreground, works cleanly with Type=simple.
- Use display :99 via xvfb-run -a so we never collide with the
physical GDM/Xorg on :0 (avoids 'server already running').
2. GNOME xstartup: switch to Ubuntu's canonical session.
- XDG_CURRENT_DESKTOP=ubuntu:GNOME (was 'GNOME'; the bare form
doesn't match Ubuntu's /usr/share/gnome-session/sessions/ entry
and apps like gnome-terminal refuse to launch).
- XDG_SESSION_TYPE=x11 (x11vnc is X11-only, so be explicit).
- GNOME_SHELL_SESSION_MODE=ubuntu (Ubuntu-patched gnome-shell hint).
3. Install extra GNOME packages needed for a usable VNC desktop.
ubuntu-desktop-minimal alone leaves the user with a blank desktop
and no way to launch apps. Add:
- gnome-shell-extension-desktop-icons-ng (desktop icons)
- gnome-terminal (terminal app)
- nautilus-extension-gnome-terminal (right-click → open in terminal)
- gnome-tweaks (advanced settings UI)
4. Two new UI options:
- 'Disable Unix socket (-nolisten unix)' — default on (avoids GDM
collision on /tmp/.X11-unix/X0).
- 'Disable X11 TCP listener (6001)' — default off (frees 6001 when
GDM is squatting on it).
5. .gitignore: exclude other projects' deliverables/ directory and
a few test output scripts (vnc_*.sh).
cnbug