nix-vnc-setup

vnc-shell.sh

# as of this gist, tigervnc fails to build on the latest nix channel.
# this gist demonstrates using older build to launch it, with openbox
nix-channel --add https://nixos.org/channels/nixos-18.09
nix-channel --update

export DISPLAY=:1
export NIX_PATH=nixpkgs=/nix/var/nix/profiles/per-user/$USER/channels/nixos-18.09

# for changing the geometry online, see https://stackoverflow.com/a/38630417
case $1 in
    init)
        mkdir -p $HOME/.vnc
        touch $HOME/.vnc/passwd
        chmod 0600 $HOME/.vnc/passwd
        cat > $HOME/.vnc/xstartup <<'EOF'
#!/bin/sh

unset SESSION_MANAGER
unset DBUS_SESSION_BUS_ADDRESS
OS=`uname -s`
if [ $OS = 'Linux' ]; then
  case "$WINDOWMANAGER" in
    *gnome*)
      if [ -e /etc/SuSE-release ]; then
        PATH=$PATH:/opt/gnome/bin
        export PATH
      fi
      ;;
  esac
fi
if [ -x /etc/X11/xinit/xinitrc ]; then
  exec /etc/X11/xinit/xinitrc
fi
if [ -f /etc/X11/xinit/xinitrc ]; then
  exec sh /etc/X11/xinit/xinitrc
fi
[ -r $HOME/.Xresources ] && xrdb $HOME/.Xresources
xsetroot -solid grey
xterm -geometry 80x24+10+10 -ls -title "$VNCDESKTOP Desktop" &
openbox &
EOF
        chmod +x $HOME/.vnc/xstartup
        nix-shell -p openbox tigervnc --run "echo asdfasdf | vncpasswd -f > $HOME/.vnc/passwd; touch $HOME/.vnc/config; vncserver -geometry 1200x1920 $DISPLAY"
        ;;
        
    add-mode)
        # ref https://github.com/ebertland/home-bin/blob/master/add-vnc-mode
        # you may be able to simply run the xrandr command without adding the mode
        GEOMETRY=$2
        DIMS=($(echo $GEOMETRY|tr 'x' ' '))
        W=${DIMS[0]}
        H=${DIMS[0]}
        FPS=$(echo "$W * $H * 60 / 1000000" | bc)
        nix-shell -p xorg.xrandr --run "
            xrandr --newmode $GEOMETRY $FPS $W 0 0 $W $H 0 0 $H
            xrandr --addmode VNC-0 $GEOMETRY
            echo 'DONE: run xrandr --fb $GEOMETRY' to change the resolution
        "
        exit
        ;;
        
    *)
        nix-shell -p openbox tigervnc
        ;;
esac