Note: Docker in Action, Second Edition

Docker
Author

Jihong Zhang

Published

March 2, 2025

1 Chapter 1 - Welcome to Docker

“Docker is a tool that makes adopting software packaging, distribution, and utilization best practices cheap and sensible defaults.”

Docker provides an expressive language that can:

  • inject environment-specific configuration
  • control access to system resources
  • built-in package management, tooling, and distribution infrastructure

1.1 What is docker?

Docker was launched in March 2013. It is an open-source Linux software for building, shipping, and running programs.

docker run dockerinaction/hello_world

docker run command tells Docker to trigger the sequence. In the command, dockerinaction/hello_world is a Docker image.

Docker runs containers. Containers are running inside virtual machines for Mac, Windows, and other OS.

Docker uses Linux namespaces and cgroups.

Following command can display information about the basic syntax.

docker help

For specific command,

docker help cp

show how to copy files from a location inside a container to a location on the host machine.

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