Update to Bullseye, make screen size configurable

Dockerfile

@@ -1,6 +1,8 @@
-# At some point maybe add variables to control size of screen.
+FROM debian:bullseye
 
-FROM debian:buster
+ENV WIDTH=1920
+ENV HEIGHT=1080
+ENV DEPTH=16
 
 RUN apt-get --yes update && apt-get --yes install --no-install-recommends \
     firefox-esr \

startup.sh

@@ -3,10 +3,10 @@
 export USER=root HOME=/root DISPLAY=:0 XAUTHORITY=$HOME/.Xauthority
 
 mkdir -p $HOME/.vnc
-echo '' | vncpasswd -f >$HOME/.vnc/passwd
+echo fnord | vncpasswd -f >$HOME/.vnc/passwd
 chmod -R go= $HOME/.vnc
 
 # -localhost
-vncserver $DISPLAY -geometry 1920x1080 -depth 16 -nolisten tcp
+vncserver $DISPLAY -geometry ${WIDTH}x${HEIGHT} -depth ${DEPTH} -nolisten tcp
 icewm
 vncserver -kill $DISPLAY