This flag is hidden within a binary that runs a webservice on a given port.
The port is blocked until the correct port knocking sequence is initiated.
The default port sequence is all of the user's salary numbers.
The commit also moves a lot of values that were previously in recipes into
attributes files for easier maintaining going forward.
Install docker from the community cookbook and add some users in the
docker group from attributes.
I created the `attributes/default.rb` attribute file to configure which
users are added in the `docker` group. I suggest to put all configurable
values here, such as users, passwords etc..
