Call out in doc to make sure DNS is set right`

[ghost]

11. Docker DNS issues should be documented:
    This isn't a huge bug per say but it took quite a bit of time to resolve so I'll call it out. So what I saw during the building of the docker image was:
    openjdk-7-jre : Depends: openjdk-7-jre-headless (= 7u51-2.4.6-1ubuntu4) but it is not going to be installed
    E: Unable to correct problems, you have held broken packages.

This led to a long goose chase, at first I had thought my variant of Ubuntu had newer version of this particular library, I even tried to downgrade my variant to match it.
The real problem here was given the way we build the docker image we essentially see next to no other output (error or not), it took a while but eventually I just pulled down a container and ran the command ... the first thing we do is apt-get update, to pull in all the packages; It turns out this was doing nothing at all, it couldn't connect with the server, why ? DNS issues in the Toronto IBM lab. The key was to add the DNS server at the very start of the docker requirements file (i.e. update /etc/resolv.conf ).

I think what we need to do here is simply call this out clearly in the docs so customers can know this may be required.