Book Image

Docker Orchestration

By : Randall Smith
Book Image

Docker Orchestration

By: Randall Smith

Overview of this book

Docker orchestration is what you need when transitioning from deploying containers individually on a single host to deploying complex multi-container apps on many machines. This book covers the new orchestration features of Docker 1.12 and helps you efficiently build, test, and deploy your application using Docker. You will be shown how to build multi-container applications using Docker Compose. You will also be introduced to the building blocks for multi-host Docker clusters such as registry, overlay networks, and shared storage using practical examples. This book gives an overview of core tools such as Docker Machine, Swarm, and Compose which will enhance your orchestration skills. You’ll learn how to set up a swarm using the decentralized building block. Next, you’ll be shown how to make the most out of the in-built orchestration feature of Docker engine and you’ll use third-party tools such as Kubernetes, Mesosphere, and CoreOS to orchestrate your existing process. Finally, you will learn to deploy cluster hosts on cloud services and automate your infrastructure.
Table of Contents (17 chapters)
Docker Orchestration
About the Author
About the Reviewer
Customer Feedback

Using Docker networks

Docker supports the concept of virtual networks. Docker Compose uses them to provide network isolation between applications. By default, every application started with Docker Compose has its own virtual network named after the application's namespace. That means, if you start two different applications with docker-compose, they will not be able to see each other.

Within an application's namespace, the network created by docker-compose provides DNS service discovery. In the case of the example multi-container application, there were DNS entries created for the web and database services called web and db, respectively. In the configuration for the web application (MyApp/, the database connection is configured to connect to a host named db. Docker does the rest by making sure that the db hostname points to the db service.


When a service is restarted, it will get a new IP address but keeps the same hostname. Make sure your application can handle this situation...