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 network services and load balancing

Mesosphere provides a number of networking services that make orchestration easier. These services provide service discovery and load balancing for running applications.

Discovering services with DNS

Every service that is created is assigned a hostname in Mesos DNS. The entries are service-name.marathon.mesos, where service-name is the name of the service in the id field. The following snippet is from a service with id set to simple-nginx. Mesos DNS would create a record named simple-nginx.marathon.mesos:

  "id" : "simple-nginx", 

Because the services are translated directly into DNS hostnames, there are a few restrictions, as follows:

  • First, names must only contain letters, numbers, and dash (-).

  • Second, the names must be shorter than 24 characters. Longer names will be shortened. This can lead to problems if two services end up with the same hostname. Tasks running in one service may be returned for the other service...