In this chapter, we discussed Puppet features that help manage Puppet environments at scale. By now, you should have a fairly good understanding on what Puppet Master is used for, how to link Puppet Agents with the Master, and how to manage the Agents' certificates. We discussed the concept of node classification and created a site.pp file that defines which classes to associate with Puppet Agents.

This chapter also introduced a couple of new Puppet language features. These features were out-of-scope variables that make variables accessible from one Puppet module to another and conditional statements to enable Puppet to apply decision-making logic to the manifest execution.

Next, in Chapter 7, Making the Configuration Dynamic, we'll learn how make use of stored configurations and PuppetDB to enable nodes to exchange configurations between them.