Master container technology and solve one of software development's most persistent headaches: the "it works on my machine" problem. Whether you are a developer or a DevOps engineer, this practical guide gives you the skills to build, share, and run modern applications reliably across any environment. Docker: Once Upon a Time is written by a Senior DevOps and Cloud Native Engineer with over a decade of experience guiding large enterprises through the complex adoption of containers and Kubernetes clusters. This book takes you on a structured journey from zero to production-ready. You will start with core container concepts and Docker installation on Mac, Windows, and Linux, then progress through image management, container networking, data persistence with volumes, and Dockerfile authoring. Each chapter includes hands-on exercises with answer keys, so you can immediately validate what you have learned. Build and publish your own images to Docker Hub, then deploy containerized workloads to the cloud using DigitalOcean App Platform. You will also gain practical experience with Docker Compose V2 to coordinate multi-service applications-including real-world use cases such as a WordPress and MariaDB stack. Written in accessible, direct language and structured from simple to advanced, Docker: Once Upon a Time requires only basic Linux system administration knowledge. No prior Docker experience is needed-just a terminal and a willingness to learn. Who This Book Is For Developers and DevOps engineers who want to get started with Docker and container technology. Basic Linux command-line familiarity is recommended; no prior Docker knowledge is required. Unique Selling Points Structured for the beginner with progressive complexity, practical exercises in every chapter, and full answer keys-making it ideal for self-paced learning Covers the complete Docker workflow end-to-end: from local installation and image creation through cloud deployment Includes a dedicated Docker Compose V2 chapter with real-world multi-service use cases, including a full Cinema application scenario and a WordPress-MariaDB production-style stack Written by Manuel Morejón, an experienced Docker practitioner and educator, under an open model Table of Contents Chapter 1: About This Book Chapter 2: Introduction to Containers Chapter 3: Installing Docker Chapter 4: First Steps with Docker Chapter 5: Container Routines Chapter 6: Publishing and Consuming Services Chapter 7: Configuration and Data Persistence Chapter 8: Building Images Chapter 9: Publishing Images Chapter 10: Deploying Containers to the Cloud Chapter 11: Docker Compose V2 Chapter 12: Recommendations and Next Steps Chapter 13: Exercise Answers