I’ve been playing with Docker recently, but not enough that I always remember the commands. Here’s my cheat sheet for future Docker use.

Cleaning up

Images

Pull an image with docker pull. For example: docker pull alpine
Remove all images not used by containers with docker image prune -a
cd into a directory containing a Dockerfile and build a container with docker build -t imagename .

Start a container from an image with docker run imagename. Docker will pull the specified image from Docker Hub if you don’t have it locally.
docker run -it imagename /bin/sh or docker run -it imagename /bin/bash to get an interactive shell into the container.
Some images specify entrypoints. In this case, override with docker run -it --entrypoint /bin/sh imagename
Usually, you want to use --rm when calling docker run to have the container automatically deleted when it exits. Remember that anything you store in the container filesystem will be deleted when the container is stopped!
Map a port from the container to your host with -p 80:4000. In this example, container port 4000 is mapped to port 80 on the host. Host first!
Create a bind mount with --volume $PWD:/site/. In this example, the current host working directory is mapped to /site/ in the container.