Docker doesn't seem to be mapping ports
I had the same problem, but following this tutorial http://ahmedalani.com/post/so-recursive-it-hurts/, says about to use the param --bind from hugo server command.
Adding that param mentioned, and the ip 0.0.0.0 we have --bind=0.0.0.0
It works to me, I think this is a natural behavior from every container taking a localhost for self scope, but if you bind with 0.0.0.0 takes a visible scope to the main host.
This is because Docker is actually running in a VM. You need to navigate to the docker-machine ip instead of localhost.
curl $(docker-machine ip):1313