# after installing Docker from https://docs.docker.com/get-docker/
# To list available commands, either run `docker` with no parameters or execute
# `docker help`
$ docker
>>> docker [OPTIONS] COMMAND [ARG...]
docker [ --help | -v | --version ]
A self-sufficient runtime for containers.
Options:
--config string Location of client config files (default "/root/.docker")
-c, --context string Name of the context to use to connect to the daemon (overrides DOCKER_HOST env var and default context set with "docker context use")
-D, --debug Enable debug mode
--help Print usage
-H, --host value Daemon socket(s) to connect to (default [])
-l, --log-level string Set the logging level ("debug"|"info"|"warn"|"error"|"fatal") (default "info")
--tls Use TLS; implied by --tlsverify
--tlscacert string Trust certs signed only by this CA (default "/root/.docker/ca.pem")
--tlscert string Path to TLS certificate file (default "/root/.docker/cert.pem")
--tlskey string Path to TLS key file (default "/root/.docker/key.pem")
--tlsverify Use TLS and verify the remote
-v, --version Print version information and quit
Commands:
attach Attach to a running container
# […]
$ docker run hello-world
# `docker run <container-name>` is used to run a container, it will pull the
# images from Docker Hub if they don't already exist in your system. Here the
# docker client connects to the daemon which in turn pulls the "hello-world"
# image from the Docker Hub. The daemon then builds a new container from the
# image which runs the executable that produces the output streamed back to the
# client that we see on our terminals.
$ docker run -d ubuntu sleep 60s
# The -d (or --detach) flag is when we want to run a container in the background
# and return back to the terminal. Here we detach an ubuntu container from the
# terminal, the output should be the id and the command exits. If we check
# running containers, we should still see ours there:
# CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
# 133261b4894a ubuntu "sleep 60s" 3 seconds ago Up 2 seconds vigorous_gould
$ docker run <container-id> -p 3000:8000
# The -p (or --publish) flag is used to expose port 8000 inside the container to
# port 3000 outside the container. This is because the app inside the container
# runs in isolation, hence the port 8000 where the app runs is private to the
# container.
$ docker run -i
# or
$ docker run -it
# Docker runs our containers in a non-interactive mode i.e. they do not accept
# inputs or work dynamically while running. The -i flag keeps input open to the
# container, and the -t flag creates a pseudo-terminal that the shell can attach
# to (can be combined as -it)
$ docker ps -a
# The `docker ps` command only shows running containers by default. To see all
# containers, use the -a (or --all) flag
# Running the above command should output something similar in the terminal:
# CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
# 82f84bf6912b hello-world "/hello" 9 minutes ago Exited (0) 9 minutes ago eloquent_sammet
$ docker stop hello-world
# or
$ docker start hello-world
# The stop command simply stops one or more containers, and the start command
# starts the container(s) up again! `docker start -a ubuntu` will attach our
# detached container back to the terminal i.e. runs in the foreground
$ docker create alpine
# `docker create` creates a new container for us with the image specified (here,
# alpine), the container does not auto-start unlike `docker run`. This command
# is used to set up a container configuration and then `docker start` to shoot
# it up when required. Note that the status is "Created":
# CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
# 4c71c727c73d alpine "/bin/sh" 29 seconds ago Created naughty_ritchie
$ docker rm 82f84
# Removes one or more containers using their container ID.
# P.S.: we can use only the first few characters of the entire ID to identify
# containers
$ docker images
# Displays all images and their information, created here means the latest image
# tag updated on Docker Hub:
# REPOSITORY TAG IMAGE ID CREATED SIZE
# ubuntu latest a8780b506fa4 9 days ago 77.8MB
# alpine latest 9c6f07244728 3 months ago 5.54MB
# hello-world latest feb5d9fea6a5 13 months ago 13.3kB
$ docker rmi
# Removes one or more images from your system which do not have their instances
# (or containers as we know them) running. If the image has an attached
# container, either delete the container first or use the -f (or --force) flag
# to forcefully delete both the container and image.
$ docker pull busybox
# The pull command downloads the specified image on our system from Docker Hub.
$ docker exec -it 7b272 bash
# This command is used to run a command in the running container's default
# directory. Here 7b272 was our ubuntu container and the above command would
# help us interact with the container by opening a bash session.
$ docker logs <container-id>
# Displays the information logged by the specified container
# root@7b27222e4bb7:/# whoami
# root
# root@7b27222e4bb7:/# pwd
# /
# root@7b27222e4bb7:/# ls
# bin boot dev etc home lib lib32 lib64 libx3 srv sys tmp usr var
# root@7b27222e4bb7:/# exit
# exit
# More commands can be found at https://docs.docker.com/engine/reference/commandline/docker/
