title: Making a karaf/docker service read a configuration file
body: <p>Starting from the io8 maven archetype, I'm setting up a Docker container containing a Karaf container containing a CXF restful web service.</p>
  
  <p>I want this to read a file when it starts up that parameterizes it. What's the procedure for setting up (a) a Docker container so that it can receive a config file when launched, and (b) finding that file from inside?</p>