Deploying Applications with Docker

Getting an application to run in a container is only the first step. The real challenge is building, configuring, securing, publishing, and deploying that application in a way you can repeat and trust.

Deploying Applications with Docker takes you from the fundamentals of images and containers to the practical decisions involved in running multi service applications on a production Docker host.

Instead of treating Docker as a collection of commands to memorize, this book follows the complete deployment workflow: build the application, test the image, package it as a versioned artifact, publish it to a registry, configure its runtime environment, deploy it, verify that it works, and recover when something goes wrong.

You will begin by developing a clear understanding of Docker Engine, images, containers, layers, registries, and the container lifecycle. You will then create your own application images and learn how Dockerfiles turn application requirements into repeatable build instructions.

As your projects become more realistic, you will learn how to:

• Build clear and maintainable Dockerfiles
• Control build context with .dockerignore
• Improve image size and build performance
• Use multi stage builds and modern BuildKit features
• Work with image repositories, tags, and immutable digests
• Publish and retrieve application images through registries
• Persist important data with volumes and appropriate storage strategies
• Connect application and database services through dedicated networks
• Understand port publishing and service discovery
• Coordinate several services with Docker Compose
• Separate development and production configuration
• Work with environment variables and secrets
• Add health checks and startup dependencies
• Read logs, inspect running services, and diagnose failures systematically
• Monitor resource usage
• Apply CPU and memory constraints
• Reduce unnecessary privileges
• Keep credentials out of images
• Scan images and strengthen the software supply chain
• Automate image testing and publishing through CI/CD
• Prepare a Docker host for production use
• Plan application updates, backups, and rollbacks

The practical exercises move from individual containers into complete multi service systems. You will connect applications to databases, add persistent storage, create isolated networks, use Compose to describe the stack, and test what happens when configuration or infrastructure fails.

The final project brings these skills together in a realistic deployment. A Python web application runs behind an Nginx reverse proxy, PostgreSQL remains on an internal network, database data is stored in a persistent volume, sensitive credentials are supplied through a Compose secret, and the application image is built, published, pulled onto a Linux host, deployed, verified, updated, and rolled back when necessary.

You will also learn why production readiness involves more than simply starting a container. Health checks, resource limits, logging, storage, network exposure, image versions, secrets, backups, and recovery procedures all contribute to a dependable deployment.

This book is suitable for developers and technical professionals who want practical container deployment skills without requiring advanced Linux administration or networking knowledge. The exercises use Docker Engine, the Docker CLI, and modern Docker Compose workflows.

Move beyond running containers locally. Build a deployment process that can package, publish, configure, verify, update, and recover real applications.