Book Image

Puppet 3: Beginner's Guide

By : John Arundel
Book Image

Puppet 3: Beginner's Guide

By: John Arundel

Overview of this book

<p>Everyone's talking about Puppet, the open-source DevOps technology that lets you automate your server setups and manage websites, databases, and desktops. Puppet can build new servers in seconds, keep your systems constantly up to date, and automate daily maintenance tasks. <br /><br />"Puppet 3 Beginner's Guide" gets you up and running with Puppet straight away, with complete real world examples. Each chapter builds your skills, adding new Puppet features, always with a practical focus. You'll learn everything you need to manage your whole infrastructure with Puppet.<br /><br />"Puppet 3 Beginner’s Guide" takes you from complete beginner to confident Puppet user, through a series of clear, simple examples, with full explanations at every stage.</p> <p>Through a series of worked examples introducing Puppet to a fictional web company, you'll learn how to manage every aspect of your server setup. Switching to Puppet needn't be a big, long-term project; this book will show you how to start by bringing one small part of your systems under Puppet control and, little by little, building to the point where Puppet is managing your whole infrastructure.</p> <p>Presented in an easy-to-read guide to learning Puppet from scratch, this book explains simply and clearly all you need to know to use this essential IT power tool, all the time applying these solutions to real-world scenarios.</p>
Table of Contents (17 chapters)
Puppet 3 Beginner's Guide
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Errors


The two main kinds of error you're likely to encounter when running Puppet are compilation errors—errors in the manifest itself, or in template files—and errors from commands executed by Puppet when applying the manifest. We'll look at these in turn.

Compilation errors

If you make a typo in the manifest, or some other kind of error, Puppet will usually alert you when you run puppet apply (or puppet parser validate). It will tell you:

  • What the error was

  • What source file, and line number, the error occurred in

Diagnosing errors

Let's take an example. If we apply a manifest containing a deliberate typo, like this (can you spot it?):

file { '/tmp/test':
  contents => 'Hello, world'
}

Puppet will complain with an error message:

ubuntu@demo:~/puppet$ papply
Error: Invalid parameter contents at /home/ubuntu/puppet/manifests/nodes.pp:4 on node demo.compute-1.internal

We actually should have said content, not contents, and Puppet is quite helpful about pointing out exactly where the problem is...