Book Image

Puppet 5 Essentials - Third Edition

By : Martin Alfke, Felix Frank
Book Image

Puppet 5 Essentials - Third Edition

By: Martin Alfke, Felix Frank

Overview of this book

Puppet is a configuration management tool that allows you to automate all your IT configurations, giving you control over what you do to each Puppet Agent in a network, and when and how you do it. In this age of digital delivery and ubiquitous Internet presence, it's becoming increasingly important to implement scaleable and portable solutions, not only in terms of software, but also the system that runs it. This book gets you started quickly with Puppet and its tools in the right way. It highlights improvements in Puppet and provides solutions for upgrading. It starts with a quick introduction to Puppet in order to quickly get your IT automation platform in place. Then you learn about the Puppet Agent and its installation and configuration along with Puppet Server and its scaling options. The book adopts an innovative structure and approach, and Puppet is explained with flexible use cases that empower you to manage complex infrastructures easily. Finally, the book will take readers through Puppet and its companion tools such as Facter, Hiera, and R10k and how to make use of tool chains.
Table of Contents (10 chapters)

Introducing classes and defined types

Puppet's equivalents to methods or functions are twofold: there are classes on one hand and defined types (also just referred to as defines) on the other.

You will find that the function analogy is a bit weak for classes, but fits defined types quite well.

They are similar at first glance, in that they both hold a chunk of reusable Puppet DSL code. There are big differences in the way each is used though. Let's take a look at classes first.

Defining and declaring classes

A Puppet class can be considered to be a container containing collections of Puppet resource declarations. It is created once (class definition) and used by all nodes that need to make use of the prepared functionality...