Much has been said about Docker and what it is good for and so forth. However sometimes you just need help doing stuff. The command line interface is documented at Use the Docker command line | Docker Documentation but some useful examples follow:docker info - gives basic info on containers and system setupdocker ps - list the currently running docker containers, with returns: Container ID, Image, Command, Created, Status, Ports, Namesdocker ps -q - list just the Container ID for the currently running docker containersdocker images - list the locally available images and all their versionsdocker image ls - same as "docker images"docker kill container_id - kill the specified docker containerdocker kill --signal=SIGKILL container_id - kill the specified docker containerdocker system prune - will remove all stopped containers as well as unused volumes and networks and dangling images
For example, let's say you want to get rid of all the old versions of an image, in which case use this:docker system prune - remove all stopped containersdocker image prune -a - remove all images not associated with a container
This only works if you have a container running the latest version though.
if you execute the following:systemctl restart docker.service
Then the Docker service will restart and every running container will be killed.
I have a Debian 9 VM running in Virtual Box, on which I followed the instructions at Get Docker CE for Debian | Docker Documentation and got Docker working, with any problems.
There are multiple ways to install on a Mac, you can use brew or brew cask or download a dmg file. I would recommend using the dmg file or "Docker for Mac" as this will automatically update and is actually an easy install, just follow the instructions at Get started with Docker for Mac | Docker Documentation and enjoy.