Book Image

Learning Docker - Second Edition

By : Vinod Singh, Pethuru Raj, Jeeva S. Chelladhurai
Book Image

Learning Docker - Second Edition

By: Vinod Singh, Pethuru Raj, Jeeva S. Chelladhurai

Overview of this book

Docker is an open source containerization engine that offers a simple and faster way for developing and running software. Docker containers wrap software in a complete filesystem that contains everything it needs to run, enabling any application to be run anywhere – this flexibily and portabily means that you can run apps in the cloud, on virtual machines, or on dedicated servers. This book will give you a tour of the new features of Docker and help you get started with Docker by building and deploying a simple application. It will walk you through the commands required to manage Docker images and containers. You’ll be shown how to download new images, run containers, list the containers running on the Docker host, and kill them. You’ll learn how to leverage Docker’s volumes feature to share data between the Docker host and its containers – this data management feature is also useful for persistent data. This book also covers how to orchestrate containers using Docker compose, debug containers, and secure containers using the AppArmor and SELinux security modules.
Table of Contents (13 chapters)

A brief on the Docker image management

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

The Docker images are 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...