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

Creating a Docker Registry

A registry is simply a place where images are stored. Already in this book, you have used a Docker Registry. In Chapter 1, Getting Started with Docker Orchestration, there was an example of starting an nginx container:

$ docker run --name webserver -p 80:80 nginx

The docker command includes the name of the image to use, in this case nginx. Docker first looks for that image locally, but if the image is not found locally, Docker connects to the default registry at the Docker Hub. If the image exists on the registry, it is downloaded and your container starts.

Think of how powerful having a registry can be. A registry makes it easy to quickly deploy any image to any node in your cluster. Without one, you have to manually build your image on each and every machine first. In my early days of using Docker, I did that and it was not fun. Each time I built an image, there was a chance that a library change would break my application. Using a registry gives you consistent...