Starting docker through Salt has always been problematic. Kubelet or
the babysitter process should start it. We've kept it around primarily
so we have a `service: docker` node for the Salt DAG.
Instead, we enable (but do not start) the Docker service in Salt. This
lets us keep the DAG node, but won't start it.
There's another bug in Salt, where watches will start the service even
on `service.enabled`. So we remove the watches, and move them to our
existing Salt bug-fix script.
The Docker 1.9.1 package on Debian is broken, and the service fails to
install when run unattended. This is treated as an installation failure
and causes everything to fail.
However, the service can be started by Salt once we're not installing
the package, and indeed we restart docker anyway.
So, on Debian, use a helper script to install the docker package. The
script sets up a policy-rc.d file to prevent the service starting, and
then cleanly removes it afterwards (this would be difficult to do in
Salt, I believe).
David McMahon