21 Days of Docker-Day 1 — Introduction to Docker

What is Docker?

Docker is an open platform for developing, shipping and running application. Its main benefit is to package applications in containers, allowing them to be portable to any system running a Linux, Mac or Windows operating system (OS).

It follows the build once and runs anywhere approach.

Docker Engine

Docker Engine is a client-server application with these major components:

  • A server which is a type of long-running program called a daemon process (the dockerd command).
  • A REST API that specifies interfaces that programs can use to talk to the daemon and instruct it what to do.
  • A command line interface (CLI) client (the docker command).
  • The CLI uses the Docker REST API to control or interact with the Docker daemon through scripting or direct CLI commands. Many other Docker applications use the underlying API and CLI.
  • The daemon creates and manages Docker objects, such as images, containers, networks, and volumes.