Preface

There are many bad ways to write a technical book. One simply rehashes the official documentation. Another walks the reader through a large and complex example, which doesn't necessarily do anything useful, except show how clever the author is. Yet another exhaustively sets out every available feature of the technology, and every possible way you can use them, without much guidance as to which features you'll really use, or which are best avoided.

Like you, I read a lot of technical books as part of my job. I don't need a paraphrase of the documentation: I can read it online. I also don't want huge blocks of code for something that I don't need to do. And I certainly don't want an uncritical exposition of every single feature.

What I do want is for the author to give me a cogent and readable explanation of how the tool works, in enough detail that I can get started using it straight away, but not so much detail that I get bogged down. I want to learn about features in the order in which I'm likely to use them, and I want to be able to start building something that runs and delivers business value from the very first chapters.

That's what you can expect from this book. Whether you're a developer, a system administrator, or merely Puppet-curious, you're going to learn Puppet skills you can put into practice right away. Without going into lots of theory or background detail, I'll show you how to install packages and config files, create users, set up scheduled jobs, provision cloud instances, build containers, and so on. Every example deals with something real and practical that you're likely to need in your work, and you'll see the complete Puppet code to make it happen, along with step-by-step instructions for what to type and what output you'll see. All the examples are available in a GitHub repo for you to download and adapt.

After each exercise, I'll explain in detail what each line of code does and how it works, so that you can adapt it to your own purposes, and feel confident that you understand everything that's happened. By the end of the book, you will have all the skills you need to do real, useful, everyday work with Puppet, and there's a complete demo Puppet repository you can use to get your infrastructure up and running with minimum effort.

So let's get started.