# gracefully:
docker stop $(docker ps -a -q) 
# forcefully:
docker kill $(docker ps -q)

# Remove all containers forcefully
docker rm -f $(docker ps -a -q)

## Remove all docker images forcefully
docker rmi -f $(docker images -q)

# remove all docker volumes
docker volume ls -qf dangling=true | xargs -r docker volume rm

# Clear everything unused
docker ps -q | xargs -r docker stop ; docker system purge -a

# Remove all containers by image:
docker rm (docker ps -a |grep [IMAGE_NAME] |awk '{print $1}')