Book Image

Extending Puppet - Second Edition

By : Alessandro Franceschi, Jaime Soriano Pastor
Book Image

Extending Puppet - Second Edition

By: Alessandro Franceschi, Jaime Soriano Pastor

Overview of this book

Puppet has changed the way we manage our systems, but Puppet itself is changing and evolving, and so are the ways we are using it. To tackle our IT infrastructure challenges and avoid common errors when designing our architectures, an up-to-date, practical, and focused view of the current and future Puppet evolution is what we need. With Puppet, you define the state of your IT infrastructure, and it automatically enforces the desired state. This book will be your guide to designing and deploying your Puppet architecture. It will help you utilize Puppet to manage your IT infrastructure. Get to grips with Hiera and learn how to install and configure it, before learning best practices for writing reusable and maintainable code. You will also be able to explore the latest features of Puppet 4, before executing, testing, and deploying Puppet across your systems. As you progress, Extending Puppet takes you through higher abstraction modules, along with tips for effective code workflow management. Finally, you will learn how to develop plugins for Puppet - as well as some useful techniques that can help you to avoid common errors and overcome everyday challenges.
Table of Contents (19 chapters)
Extending Puppet Second Edition
Credits
About the Authors
About the Reviewer
www.PacktPub.com
Preface
Index

Sample architectures


We have outlined the main tasks and components we can use to put things together in a Puppet architecture; we have given a look at Foreman, Hiera, and at the roles and profiles pattern; now let's see some real examples based on them.

The default approach

By default, Puppet doesn't use an ENC and lets us classify nodes directly in /etc/puppet/manifests/site.pp (or in files imported from there) with the node statement. So a very basic setup would have site.pp with content like the following:

node www01 {
  # Place here resources to apply to this node in Puppet DSL:
  # file, package service, mount...
}
node lb01 {
  # Resources for this node: file, package service...
}

This is all we need: no modules with their classes, no Hiera, no ENC; just good old plain Puppet code as they teach us in schools, so to speak.

This basic approach, useful just for the first tests, obviously does not scale well and would quickly become a huge mess of duplicated code.

The next step is to use classes...