In this chapter, we met Docker Swarm, defined its aims, features, and architecture. We also reviewed some of the other possible open source alternatives to Swarm, and their relationships with it. Finally, we installed and started using Swarm by creating a simple local cluster made of four hosts on Virtualbox and on Digital Ocean.

Clusterize containers with Swarm will be the main topic for the whole book, but before we start using Swarm in production, we'll understand some theory before, beginning with the discovery services, the topic of Chapter 2, Discover the Discovery Services.