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

Chapter 2. Building Multi-Container Applications with Docker Compose

Modern applications have a lot of moving parts. A web application almost always uses a database such as MySQL or MongoDB to store data. There may be a load balancer or SSL proxy. Often there are tasks scheduled to run regularly that perform routine maintenance or backups. On a traditional server, these tasks might all be installed on a single server or spread across numerous hosts. The challenge faced by system administrators is how are all these parts deployed consistently and reliably?

Rather than having a single container that does everything, you can split your application into smaller chunks. Each container has a specific task and does only that task. For example, you might have one image that is a Perl-based web application; a second that runs MySQL; a third that runs HAProxy to load balance and provide SSL termination for the Perl application. Each separate container can be run, upgraded, and tested independent of...