Docker containers hold the promise of breaking down barriers between development and operations, avoiding platform lock-in and easing installation and configuration of common components. This practical book will take you through the fundamentals of Docker, explaining common idioms and pointing out potential pitfalls. It guides you through the creation and deployment of a simple webapp, showing how Docker can be used at all stages, including development, testing and deployment. Other topics in this book include using Docker to provide a microservices architecture, how to best do service discovery, and how to bundle applications using Docker. You'll also get an overview of the large ecosystem that has sprung up around Docker, including the various PaaS offerings and configuration tools.