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

Time for action – running an arbitrary command


  1. Modify your manifests/nodes.pp file as follows:

    node 'demo' {
      exec { 'Run my arbitrary command':
        command => '/bin/echo I ran this command on `/bin/date` >/tmp/command.output.txt',
      }
    }
  2. Run Puppet:

    ubuntu@demo:~/puppet$ papply
    Notice: /Stage[main]//Node[demo]/Exec[Run my arbitrary command]/returns: executed successfully
    Notice: Finished catalog run in 0.14 seconds
  3. Check the output produced (you won't see exactly the same date and time shown here, unless you're a Time Lord):

    ubuntu@demo:~/puppet$ cat /tmp/command.output.txt 
    I ran this command on Mon Dec 17 16:14:04 UTC 2012

What just happened?

The line exec { 'Run my arbitrary command': declares an exec resource with the name Run my arbitrary command . The name can be anything; it's not otherwise used by Puppet, except that like all resource names it can't be the same as another instance of the same resource type.

The command to run is specified by the following line:

command => '/bin...