Chapter 1. Discovering Docker

 

This chapter covers

  • What Docker is
  • The uses of Docker and how it can save you time and money
  • The differences between containers and images
  • Docker’s layering feature
  • Building and running a to-do application using Docker

Docker is a platform that allows you to “build, ship, and run any app, anywhere.” It has come a long way in an incredibly short time and is now considered a standard way of solving one of the costliest aspects of software: deployment.

Before Docker came along, the development pipeline typically involved combinations of various technologies for managing the movement of software, such as virtual machines, configuration management tools, package management systems, and complex webs of library dependencies. All these tools needed to be managed and maintained by specialist engineers, and most had their own unique ways of being configured.

Docker has changed all of this, allowing different engineers involved in this process to effectively speak one language, making working together a breeze. Everything goes through a common pipeline to a single output that can be used on any target—there’s no need to continue maintaining a bewildering array of tool configurations, as shown in figure 1.1.

Figure 1.1. How Docker has eased the tool maintenance burden

1.1. The what and why of Docker

1.2. Building a Docker application

Summary