10: Docker Swarm

Now that we know how to install Docker, pull images, and work with containers, the next thing we need is a way to work with things at scale. That’s where Docker Swarm comes into play.

As usual, we’ll split this chapter into the usual three parts:

• The TLDR
• The deep dive
• The commands

Docker Swarm - The TLDR

Docker Swarm is two main things:

1. An enterprise-grade secure cluster of Docker hosts
2. An engine for orchestrating microservices apps

On the clustering front, Swarm groups one or more Docker nodes and lets you manage them as a cluster. Out-of-the-box, you get an encrypted distributed cluster store, encrypted networks, mutual TLS, secure cluster join tokens, and a PKI that makes managing and rotating certificates a breeze. You can even non-disruptively add and remove nodes. It’s a beautiful thing.

While we cover some aspects of Swarm security in this chapter, we go a lot deeper in Chapter 15.

On the orchestration front, Swarm...