Now that we've experienced the traditional Linux way to deploy an application, let's turn to Docker, which is a popular new way to manage application deployment.

Docker (http://docker.com) is a cool new tool in the software industry. It is described as an open platform for distributed applications for developers and sysadmins. It is designed around Linux containerization technology and focuses on describing the configuration of software on any variant of Linux.

A Docker container is a running instantiation of a Docker image. A Docker image is a bundle containing a specific Linux OS, system configuration, and application configuration. Docker images are described using a Dockerfile, which is a fairly simple-to-write script describing how to build a Docker image. The Dockerfile starts by specifying a base image from which to...