Docker for Beginners

A Docker image is like a virtual machine image.

A running instance of a Docker image is known as a Docker container.

You could think of a Docker container as a virtual machine instance with almost no performance overhead.

Install Docker Runtime

The Docker runtime is like a virtual machine management system, say, VirtualBox or VMware.

Installers

1. For Mac: https://download.docker.com/mac/stable/Docker.dmg
2. For Windows: https://download.docker.com/win/stable/Docker%20for%20Windows%20Installer.exe
3. For Linux: https://docs.docker.com/engine/installation/

Test if it's properly installed

Open 'Terminal'(Mac) or 'Commandline'(Windows), type the command docker version. If you see both client and server versions like the following, you are ready to go.

$ docker version
Client:
 Version:      17.09.0-ce-rc1
 API version:  1.31
 Go version:   go1.8.3
 Git commit:   ae21824
 Built:        Wed Sep  6 22:25:36 2017
 OS/Arch:      darwin/amd64

Server:
 Version:      17.09.0-ce-rc1
 API version:  1.32 (minimum version 1.12)
 Go version:   go1.8.3
 Git commit:   ae21824
 Built:        Wed Sep  6 22:31:19 2017
 OS/Arch:      linux/amd64
 Experimental: true

Usage

To download and run an image

docker run paddlepaddle/book

where paddlepaddle/book is the image id in Dockerhub. Here we omit tag name, docker will use latest by default.

If you see messages of the following form

Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?

It means you need to run Docker so the daemon is on.

To deploy, run an image and interact with it via command line

docker run -t paddlepaddle/book

where -t means keeping the instance in the foreground and interact with it like you logged in a remote machine.

To deploy, run, interact and also mount a local folder into it

docker run -t -v /foo:/bar paddlepaddle/book

where -v /foo:/bar means mounting your local machine's folder '/foo' to container's '/bar' path

To deploy, run, interact, mount, and forward a host port to container's

docker run -t -v /foo:/bar -p 80:8080  paddlepaddle/book

where -p 80:8080 means any request to host's 80 port will be forwarded to container's 8080 port.

To list all containers running

docker ps

if you need to list containers in 'stopped' state, use docker ps -a.

To stop a container

docker stop 591a09a8a5be

where 591a09a8a5be is the container id which you can find from docker ps.

if docker stop is not powerful enough, try docker kill

To restart a container

docker restart 591a09a8a5be

To re enter a container

1. first make sure the container is running. use

docker ps -a

and check STATUS.

2. attach it

docker attach $container_id

where 591a09a8a5be is the container id.

Additonal Documentation

https://docs.docker.com/