This chapter explains how to set up a Swift cluster on top of Docker. Let's briefly delve into Docker to make this chapter easier to understand. Docker is all about making it easier to create, deploy, and run applications using containers. Containers allow a developer to package an application with all the parts it needs, such as libraries and other dependencies, and ship it as one package.

Docker is a bit like a virtual machine. However, unlike a virtual machine, where a complete virtual operating system gets installed, Docker allows applications to use the same Linux kernel as the system they're running on, and only requires applications to be shipped with things not already running on the host computer. Refer to the following diagram:

A Docker container versus a virtual machine

Virtual machines have a full operating system with their own memory management installed with the associated overhead of virtual device drivers. In a virtual machine, valuable resources...