Manage Docker as a non-root user

The Docker daemon binds to a Unix socket instead of a TCP port. By default that Unix socket is owned by the user root and other users can only access it using sudo. The Docker daemon always runs as the root user.

If you don’t want to preface the docker command with sudo, create a Unix group called docker and add users to it. When the Docker daemon starts, it creates a Unix socket accessible by members of the docker group.

1. Create the docker group: sudo groupadd docker
2. Add your user to the docker group: sudo usermod -aG docker $USER
3. Log out and log back in so that your group membership is re-evaluated.

Docker Commands

General

Command	Description
docker	lists all the commands available in docker
docker version	verified client can talk to engine
docker info	more info on configureation and setup
docker <command> (options)	old (still works)
docker <command> <subcommand> (options)	new

Running Container

Command	Description
docker container run --publish 80:80 nginx	running container
docker container run --publish 80:80 --detach nginx	running container + detach
docker container run --publish 80:80 --detach --name <container> nginx	running container + detach + name assignment
docker container ls	list of running containers
docker ps	list of running containers
docker container ls -a	list of all created containers so far
docker container logs <container>	getting logs of container

Note: -d is equat to --detach

Removing Container

Command	Description
docker container stop <CONTAINER_ID>	stopping container
docker container start <CONTAINER_ID>	starting container
docker container rm <container_id>	removing an stopped container
docker container rm -f <container_id>	removing a running container (forced)

Command	Description
docker top <container>	process list in one container

Environment Variable

Command	Description
docker top <container>	displays the processes of <container> container

Command	Description
docker container inspect <container>	details of one container config(startup config, volumes, networking, etc)
docker container stats	performance stats for all containers

Shell Inside Container

• -t (pseudo-tty) simulates a real terminal, like what SSH does.
• -i (interactive) keep session open to receive terminal input.
• Docker usage: docker container run [OPTIONS] IMAGE [COMMAND] [ARG...]

Command	Description
docker container run -it --name proxy nginx bash	start new container interactively

Command	Description
docker container start -ai ubuntu	start existing container interactively

Run Additional Process in Running Container

Command	Description
docker container exec -it ubuntu	run additional command in existing container

Docker Networks

Command	Description
docker container run -p	run additional command in existing container
docker container port <container>

Images

An image is an ordered collection of root filesystem changes and the corresponding execution parameters for use within a container runtime.