Dockerfile for VNC firefox "sandbox"

Dockerfile

# Firefox over VNC
#
# VERSION               0.1
# DOCKER-VERSION        0.2

from    ubuntu:12.04
# make sure the package repository is up to date
run     echo "deb http://archive.ubuntu.com/ubuntu precise main universe" > /etc/apt/sources.list
run     apt-get update

# Install vnc, xvfb in order to create a 'fake' display and firefox

run     apt-get install -y x11vnc xvfb
run     mkdir /.vnc
# Setup a password
run     x11vnc -storepasswd 1234 ~/.vnc/passwd
# Autostart firefox (might not be the best way to do it, but it does the trick)
run     bash -c 'echo "firefox" >> /.bashrc'

Not working, dies with
Step 6/7 : RUN x11vnc -storepasswd 1234 ~/.vnc/passwd
---> Running in fbbe7a6ab373
storepasswd: No such file or directory
-storepasswd failed for file: /root/.vnc/passwd
The command '/bin/sh -c x11vnc -storepasswd 1234 ~/.vnc/passwd' returned a non-zero code: 1