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)

Sharing data between containers

In the previous section, you learned how seamlessly the Docker Engine enables data sharing between the Docker host and the container. Although it is a very effective solution for most of the use cases, there are use cases wherein you will have to share data between one or more containers. The Docker's prescription to address this use case is to mount the data volume of one container to other containers using the --volume-from option of the docker run subcommand.

Data-only containers

Before Docker introduced the top-level volume management feature, the data-only container was the recommended approach to achieve data persistency. It is worth understanding data-only containers because you will find many implementations that are based...