A single script for starting, connecting to, and stopping a VNC server

vnc.sh

#!/bin/bash

# Here's how this works:
#   1) Open an SSH session
#      a) Include a tunnel. Use port 5900 locally (default for VNC) and port 5901 remotely (default for tightvncserver).
#      b) The SSH commands are run in the backgroud (so we can run other commands before they finish.
#      c) Start tightvncserver.
#      d) After starting tightvncserver, wait an extra 10 seconds before closing the SSH session (and the SSH tunnel). See below for when the SSH tunnel is actually closed. Note: you would need to increase this in order to have enough time to enter the password if you aren't using the passwd option to point to a password file.
#   2) Sleep 5 seconds. This gives enough time for the tightvncserver to start running.
#   3) Connect to VNC using the SSH tunnel and the password stored in /path/to/passwd. Once we do this, the SSH tunnel will be forced to stay open as long as our VNC session is open.
#   4) After the VNC session closes, shut off tightvncserver.

# Useful: http://www.g-loaded.eu/2006/11/24/auto-closing-ssh-tunnels/



# Options
# -s   Server name (hostname) or IP address
# -p   SSH port
# -u   User name to use for SSH tunnel
# -t   Client-side sleep time
# -i   Server-side sleep time. Must be greater than client-side sleep time. Defaults to double the client-side sleep time.
# -a   Password file
# -g   Geometry (screen resolution)
# -c   Color depth
# -d   Display number. This implies the port on the server side, which is always 5900 plus the display number.
# -o   Client port

while getopts ":s:p:u:t:i:a:g:c:d:o:" opt; do
  case $opt in
    s)
      SERVER=$OPTARG
      ;;
    p)
      SSH_PORT=$OPTARG
      ;;
    u)
      USER=$OPTARG
      ;;
    t)
      CLIENT_SLEEP=$OPTARG
      ;;
    i)
      SERVER_SLEEP=$OPTARG
      ;;
    a)
      PASSWORD_FILE=$OPTARG
      ;;
    g)
      GEOMETRY=$OPTARG
      ;;
    c)
      COLOR=$OPTARG
      ;;
    d)
      # NOTE: We can't just set the server port because doing that stops us from killing
      #       the server easily from within this script.
      SERVER_DISPLAY=$OPTARG
      ;;
    o)
      CLIENT_PORT=$OPTARG
      ;;
    \?)
      echo "Invalid option: -$OPTARG" >&2
      exit 1
      ;;
    :)
      echo "Option -$OPTARG requires an argument." >&2
      exit 2
      ;;
  esac
done


# Set defaults

[ -n "$SERVER" ] || SERVER=myservername
[ -n "$SSH_PORT" ] || SSH_PORT=22
[ -n "$USER" ] || USER=paul
[ -n "$CLIENT_SLEEP" ] || CLIENT_SLEEP=1
[ -n "$SERVER_SLEEP" ] || SERVER_SLEEP=$(($CLIENT_SLEEP*2))
if [ "$CLIENT_SLEEP" -ge "$SERVER_SLEEP" ]; then
  echo "ERROR: Server sleep time must be greater than client sleep time."
  echo "       SERVER_SLEEP: $SERVER_SLEEP"
  echo "       CLIENT_SLEEP: $CLIENT_SLEEP"
  exit 3
fi
[ -n "$PASSWORD_FILE" ] || PASSWORD_FILE=/path/to/passwd
[ -n "$GEOMETRY" ] || GEOMETRY=1275x710
[ -n "$COLOR" ] || COLOR=8
[ -n "$SERVER_DISPLAY" ] || SERVER_DISPLAY=1
[ -n "$SERVER_PORT" ] || SERVER_PORT=$((5900+$SERVER_DISPLAY))
[ -n "$CLIENT_PORT" ] || CLIENT_PORT=5900



ssh -f -L $CLIENT_PORT:localhost:$SERVER_PORT $USER@$SERVER -p $SSH_PORT "tightvncserver -nolisten tcp -localhost -nevershared -geometry $GEOMETRY -depth $COLOR :$SERVER_DISPLAY -rfbport $SERVER_PORT && sleep $SERVER_SLEEP" \
        && sleep $CLIENT_SLEEP \
        && vncviewer -encodings "tight" -passwd $PASSWORD_FILE localhost::$CLIENT_PORT \
        && ssh $USER@$SERVER -p $SSH_PORT "tightvncserver -kill :$SERVER_DISPLAY"