container commands	effect
docker ps	shows all running containers
docker ps -a	shows all containers (running or not)
docker stop <id> or <name>	stops a container
docker rm <id> or <name>	removes a stopped or exited container permanently
docker exec <container_name> or <container_id> *my_command*	runs a command inside an instance of a running container
docker attach <container_name> or <container_id>	attach to a container that's running the background (access the shell)
docker container prune	remove all stopped containers
docker container run -it -p 127.0.0.1:3000:3000 --link pg -e POSTGRES_HOST=pg -e POSTGRES_USER=postgres -e POSTGRES_PASSWORD=secret my_username/rails_app:v1	runs a new container that with interactive shell -it that links the localhost port 127.0.0.1:3000:3000 to localhost:3000 on our machine to a postgres container --link and environment variables used by database.yml with the -e POSTGRES_HOST=pg etc
docker exec -it <container_name> <command>	attaches to an instance of a running container and runs command opening STDIN interactivity

image commands	effect
docker images	shows all images
docker rmi <image_id> or <name>	removes an image
docker run <image_name>	runs a container based on an image (if not on system it will download it)
docker run -d <image_name>	runs a container from the image in the background (no shell or output console is shown)
docker pull <image_name>	downloads an image but does not run a container
docker run -it <image_name>	opens container with STDIN prompt based off an image
docker run -p 3000:3000 <image_name>	opens a container with the ip address accessible by the host
docker run --name myname image:1.13-image	run a container based on an image and give it a name

volume commands	effect
docker volume ls	list current volumes
docker volume rm <volume_name>	remove a volume
docker container run --name pg -d -v ws-pg-data:/var/lib/postgresql/data -e POSTGRES_USER=postgres -e POSTGRES_PASSWORD=secret postgres:10.6-alpine	runs a pg container in detached mode -d and creates a volume called ws-pg-data -v outside of the container that is mounted to it and environment variables are passed to the container as well with -e

docker-compose commands	effect
docker-compose up	uses the docker-compose.yml file in the current directory to start services (can be run in detached mode -d)
docker-compose ps	see current running containers built from the docker-compose.yml file
docker-compose logs	see the logs from both running compose containers
docker-compose up -d --build
docker-compose attach <container_name>	Get into container session STDIN and have the ability type commands in the container (works well for byebug)

remove unused dangling images, containers, volumes and networks docker system prune docker system prune --volumes : removes all volumes docker system prune -a will remove all unused images (not just dangling images)

remove unused or stale containers

docker container rm <container_id> docker container prune

run command line in image docker container run -it my_username/cowsay:v1 bash