Puts John the Ripper in a container.
Building the container will pull down the latest source from the github repo.
If you have special requirements for building you should fork this repo and edit the Docker file.
If you want the absolute best performance you should clone this repo and run docker build . on the machine you will be running the container on. It will build with any hardware optimizations your system/kernel provides.
Crack local passwords of host system
sudo unshadow /etc/passwd /etc/shadow ./passwords
docker run -v ${PWD}:/run rothgar/john /run/passwords