Quick tech tip, mostly for me to remember.
When running docker containers on OSX it can act a little weird.
Because Docker is running as a VM, when you do a port binding via :
docker run - p localhostport:containerport
The container port is actually bound to the IP bound to docker VM, and not necessarily to localhost.
Be sure to run a docker-machine ip default to verify what the address is for the VM.
so if docker-machine ip default
then accessing the localport for a mapped container port would be 192.168.100.100:localhostport
Hopefully this saves some one else from pulling their hair out.