This book will not teach you DevOps practices. It will not show you how Docker works. It will not explore how to build images, deploy services, operate Swarm clusters, nor how to do continuous deployment. We will not develop microservices nor will we go through practices and tools that allow us to create and manage our infrastructure. This book assumes that you already know all that. If you do not, please read The DevOps 2.0 Toolkit: Automating the Continuous Deployment Pipeline with Containerized Microservices for a general overview of DevOps tools and practices and The DevOps 2.1 Toolkit: Docker Swarm: Building, testing, deploying, and monitoring services inside Docker Swarm clusters for an in depth examination of how Docker Swarm clusters work.