Docker image for shadow (https://github.com/shadow/shadow). Reason for making my own docker image was that the old one is really old (fedora 22) and the dockerfile used isnt public.
docker build . -t nemcrunchers/shadow
docker run -t -i -u shadow --sysctl kernel.shmmax=1073741824 --tmpfs /dev/shm:rw,nosuid,nodev,exec,size=1g nemcrunchers/shadow /bin/bash