As we have seen in the previous chapter and this chapter, there are many ways of getting a handle on a Docker image. You could download a fully set up application stack from the public repository by using the docker pull subcommand. Otherwise you could craft your own application stack either manually by using the docker commit subcommand or automatically by using Dockerfile and the docker build subcommand combination.

The Docker images are being positioned as the key building-blocks of the containerized applications that, in turn, enable the realization of distributed applications, which will be deployed on the cloud servers. The Docker images are built in layers, that is, the images can be built on top of other images. The original image is called the parent image and the one that is generated is called the child image. The base image is a bundle, which comprises an application's common dependencies. Each change that is made to the original...