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

Comparison operators


Puppet supports some common comparison operators, which resolve to true or false:

  • Equal ==, returns true if the operands are equal. Used with numbers, strings, arrays, hashes, and Booleans. For example:

    if $::osfamily == 'Debian' { [ ... ] }
  • Not equal != , returns true if the operands are different:

    if $::kernel != 'Linux' { [ ... ] }
  • Less than < , greater than >, less than or equal to <=, and greater than or equal to >= can be used to compare numbers:

    if $::uptime_days > 365 { [ ... ] }
    if $::operatingsystemrelease <= 6 { [ ... ] }
  • Regex match =~ compares a string (left operator) with a regular expression (right operator), and resolves true, if it matches. Regular expressions are enclosed between forward slashes and follow the normal Ruby syntax:

    if $mode =~ /(server|client)/ { [ ... ] }
    if $::ipaddress =~ /^10\./ { [ ... ] }
  • Regex not match !~, opposite to =~, resolves false if the operands match.