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

Extending compose files

We have already talked about using environment files to change your application's behavior. Another way that you can do that is to use multiple Docker Compose files. Each file builds on the previous one, extending it and possibly overriding options. This can give you great flexibility in developing your application or adjusting it to fit different environments. This can be done in one of the following two ways:

  • The first way is to put your overrides in a file named docker-compose.override.yml. This file is read automatically by docker-compose. The options in docker-compose.yml are applied first and then the options in docker-compose.override.yml are applied.

  • The second option is to use the -f flag to docker-compose. You may include as many compose files as you want. They will be applied in order from left to right. For example, in the docker-compose -f docker-compose.yml -f docker-compose-prod.yml command, docker-compose.yml is read first then docker-compose-prod.yml...