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)

Avoiding common pitfalls

Until now, we have discussed how effectively data volumes can be used to share data between the Docker host and the containers as well as between containers. Data sharing using data volumes is turning out to be a very powerful and essential tool in the Docker paradigm. However, it does carry a few pitfalls that are to be carefully identified and eliminated. In this section, we make an attempt to list out a few common issues associated with data sharing and the ways and means to overcome them.

Directory leaks

Earlier in the Data volume section, you learned that the Docker Engine automatically creates directories based on the VOLUME instruction in the Dockerfile as well as the -v option of the docker run subcommand. We also understood that...