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

Connecting containers with overlay networks

When Docker containers are started, they are assigned a private IP address. This avoids conflicts with addresses that may already be in use on the network and allows containers on the same host to talk to each other. It is a nice system except that containers running on different hosts cannot talk to each other unless they are exposed on the hosts. To solve this problem, various projects, including Docker, developed overlay networks.

An overlay network is a private network that is layered on top of an existing IP network to allow containers on multiple hosts to talk to each other. Containers connected to an overlay network are still assigned private addresses and are not accessible from outside the network. Ports can be made public using the -p option to docker run as normal.

Docker's pluggable network infrastructure has led to a growth in the number of overlay plugins. It also allows for containers to use multiple overlays networks. Using multiple...