Docker in mac hostconfig.json

https://www.softwareab.net/wordpress/docker-macosx-modify-hostconfig-existing-container/

screen /Users/#USER/Library/Containers/com.docker.docker/Data/com.docker.driver.amd64-linux/tty

cd /var/lib/docker/containers/${container_hash}/hostconfig.json

to reset docker

http://stackoverflow.com/questions/19335444/how-to-assign-a-port-mapping-to-an-existing-docker-container

1) stop the container 
2) change the file
3) restart your docker engine (to flush/clear config caches)
4) start the container