Docker Cookbook

Chapter 6. Optimized Operating System Distributions for Docker

6.0 Introduction

In the first chapter we covered several installation scenarios. They showed how to install Docker on traditional operating systems. In this chapter we present a new generation of operating systems (OSes) that are optimized for Docker. These new OSes consider two new trends. First, they consider that everything running in a server will be a container. Second, they try to implement an atomic upgrade mechanism to simplify operation and maintenance of servers in the data center. This means that these new operating systems do not feature a traditional package manager like yum or apt, but instead they assume that you will get your application running in the machine by pulling a Docker image and running a container. These OSes provide just the minimum required to run containers.

The first operation system presented is CoreOS (see Recipe 6.1). CoreOS is available on several public cloud providers. It can be installed on bare-metal and can be tested locally via Vagrant or by building your own ISO. In Recipe 6.2 we show how to configure a CoreOS instance, in Recipe 6.3 we present how to create a cluster of CoreOS machines, and in Recipe 6.4 we see how we can use the native system-based scheduler to launch containers on a CoreOS cluster. We then have a look a Flannel, a network overlay technique that comes bundled in CoreOS. Flannel, as we mentioned in the networking chapter, provides you with a networking solution ...