title: Access Docker from external machine in network
body: <p>Is it possible to access an docker service from an external device? 
  I built the service via fig and exposed the port 3000. I use fig with docker-osx, so docker is running inside a virtualbox. </p>
  
  <p>Now I need to access the service provided from an external device (i.e. a mobile phone or tablet). </p>
  
  <p>At the moment I could only access the service with localdocker:3000 from the machine hosting the VirtualBox-Environment. </p>