ubuntu_docker/scripts/entrypoint.sh

#!/bin/bash
set -e

VNC_PASSWORD="${VNC_PASSWORD:-changeme}"
RESOLUTION="${RESOLUTION:-1280x800}"

if [ "$VNC_PASSWORD" = "changeme" ]; then
    echo "WARNING: using default VNC password 'changeme'. Set VNC_PASSWORD in your .env file." >&2
fi

# This tigervnc build ships no vncpasswd tool; it authenticates VNC's "Plain"
# security type against the Unix account password via PAM instead.
echo "ubuntu:${VNC_PASSWORD}" | sudo chpasswd

mkdir -p "$HOME/.vnc"
cp /opt/vnc/xstartup "$HOME/.vnc/xstartup"
chmod +x "$HOME/.vnc/xstartup"

# Clean up any stale lock/pid files from a previous run of this volume
vncserver -kill :1 >/dev/null 2>&1 || true
rm -f /tmp/.X1-lock /tmp/.X11-unix/X1

vncserver :1 -geometry "$RESOLUTION" -depth 24 -localhost no \
    -SecurityTypes Plain -PlainUsers ubuntu

websockify --web=/usr/share/novnc/ 6901 localhost:5901 &

LOGFILE="$HOME/.vnc/$(hostname):1.log"
touch "$LOGFILE"
exec tail -f "$LOGFILE"