The idea behind Docker is simple. Create a tiny virtual environment called a container that holds just your application and its dependencies. The Docker engine uses the host operating system to keep track of your containers. Applications running inside containers share resources, making their footprints small. They are easy to install, manage, and remove. Docker in Action, Second Edition teaches you to create, deploy, and manage applications hosted in Docker containers running on Linux. Fully updated, with four new chapters and revised best practices and examples, this second edition begins with a clear explanation of the Docker model. Then, you go hands-on with packaging applications, testing, installing, running programs securely, and deploying them across a cluster of hosts. With examples showing how Docker benefits the whole dev lifecycle, you'll discover techniques for everything from dev-and-test machines to full-scale cloud deployments.

DESCRIPTION The idea behind Docker, a free an open source program, is simple. Create a tiny virtual environment, called a container, for an application that includes only its particular set of dependencies. The Docker engine accounts for, manages, and builds these containers through functionality provided by the host operating system. Software running inside containers share the Linux OS and other resources, making their footprints radically smaller, and the containerized applications easy to install, manage, and remove. Applications can be packaged without worrying about environment-specific deployment concerns, and the operations team gets cleaner, more efficient systems across the board. Docker in Action starts with a clear explanation of the Docker model of virtualization and shows how to create, deploy, and manage applications hosted in Docker containers. It offers specific techniques for testing and distributing applications via Docker Hub and other registries. It shows how to take advantage of the Linux OS features that Docker uses to run programs securely, and how to manage shared resources. Using carefully-designed examples, the book guides readers on orchestrating containers and applications from installation to removal. Along the way, it teaches techniques for using Docker on systems ranging from personal dev-and-test machine to full-scale cloud deployments. KEY SELLING POINTS Explains the "why" and "how" of Docker Simplify software installation Addresses many of the everyday software problems faced by developers AUDIENCE Readers need a working knowledge of installing and running software on the Linux OS. No prior experience with Docker or other virtualization technologies is required. ABOUT THE TECHNOLOGY Docker provides software logistics. It uses "container" abstraction to hide complex tooling for packaging software, and running software in virtualized environments without overhead of a full virtual machine. Docker and the container abstraction are driving a change in the way people write, test, deploy, and distribute software.