If you run into a situation where you have thousands or tens of thousands of dead containers and you run the usual docker rm `docker ps -a -q` either docker will bomb saying too many arguments or you'll see that as the list of containers being killed grows the process slows down. It seems the docker process amasses all the open files until it's …

flush-old-docker-containers.sh

while [[ `docker ps -a -q | wc -l` -gt `docker ps -q | wc -l` ]]; do docker rm ` docker ps -a -q | head -n 25`; done