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

Roles and profiles


In 2012, Craig Dunn wrote a blog post (http://www.craigdunn.org/2012/05/239/), which quickly became a point of reference on how to organize Puppet code. He discussed roles and profiles. The role describes what the server represents: a live web server, a development web server, a mail server, and so on. Each node can have one, and only one, role. Note that in his post he manages environments inside roles (two web servers on two different environments have two different roles), as follows:

node www1 { 
  include ::role::www::dev
}
node www2 { 
  include ::role::www::live
}
node smtp1 { 
  include ::role::mailserver
}

Then he introduces the concept of profiles, which include and manage modules to define a logical technical stack. A role can include one or more profiles:

class role { 
  include profile::base
}
class role::www inherits role {
  include ::profile::tomcat
}

In environment related sub roles, we can manage the exceptions we need (here, for example, the www::dev role...