Puppet 3 Beginner's Guide

Those nice people at Packt Publishing have asked me to write a follow-up to the surprisingly successful Puppet Cookbook. This book, the Puppet 3 Beginner’s Guide caters for those who are completely new to Puppet, and take you through installation, setup, writing your first manifests, using Git to manage and distribute your manifests, managing users, reporting and troubleshooting, and a few other useful things.

Buy the Puppet 3 Beginner’s Guide on Amazon.com (Kindle edition)

Buy the Puppet 3 Beginner’s Guide on Amazon.co.uk (Kindle edition)

Some of the most respected people working in devops and configuration management have contributed to the book’s development by reading early chapters, giving feedback, testing code, and making suggestions.

Outline

Introduction to Puppet

What’s the problem with computers?

In this chapter you’ll learn what Puppet is, and what it can help you do. Whether you’re a system administrator, a developer who needs to fix servers from time to time, or just someone who’s annoyed at how long it takes to set up a new laptop, you’ll have come across the kind of problems Puppet is designed to solve.

What is configuration management?
What problems is Puppet trying to solve?
How do you work differently as a systems administrator using Puppet?

First steps with Puppet

In this chapter you’ll learn how to install Puppet, how to write your first manifest, and how to put Puppet to work configuring a server. You’ll also understand how Puppet reads and applies a manifest.

Installing Puppet
Creating your first manifest
Making your first changes on a machine with Puppet

Packages, files, and services

The most common types of resources you’ll manage with Puppet are packages, files, and services. They often occur together, with a package providing a service, and the service requiring a configuration file. In this chapter you’ll see how to use Puppet to manage these resources effectively.

Managing packages
Managing services
Resource dependencies
Managing config files
The package - file - service pattern
A complete worked example using Nginx and a simple website

Managing Puppet with Git

In this chapter you’ll learn how to use the Git version control system to manage your Puppet manifests. I’ll also show you how to use Git to distribute the manifests to multiple machines, so that you can start managing your whole network with Puppet.

Introduction to Git
Using Git to version control your Puppet code
Committing changes
Looking at revision history
Reverting changes
Merging commits
Using Git to deploy Puppet manifests to multiple servers
Setting up remote access to Git
Pulling updates and running Puppet from cron
Using feature branches

Managing users

In this chapter you’ll learn how to use Puppet to create and manage user accounts, configure SSH access and keys, and control user privileges via sudo.

Creating user accounts with Puppet
Configuring SSH
Distributing SSH keys
Controlling sudo privileges
Locking and removing user accounts.

Tasks and templates

In this chapter you’ll learn how to use Puppet’s resource types to run commands, schedule regular tasks, and distribute large trees of files. You’ll also find out how to insert values dynamically into files using templates.

Using exec resources to run commands
Using cron resources to run scheduled jobs
Deploying trees of files
Using templates

Definitions and classes

In this chapter you’ll learn how to group resources into reusable clumps that you can refer to by name, making it easy to create lots of similar resources at once. You can also make your Puppet manifests shorter, neater, and more readable by eliminating duplicated code.

Arrays
Definitions
Parameters
Classes

Expressions and logic

In this chapter you’ll learn how to make choices in your Puppet manifests, how to do arithmetic, logic, and string operations in the Puppet language, and how to use regular expressions to match patterns in strings. You’ll also find out about some useful Puppet data types: arrays and hashes.

If statements
Case statements
Selectors
Operators
Regular expressions
Capture variables
Regular expression substitutions
Arrays and hashes
Multi-level hashes

Reporting and troubleshooting

In this chapter you’ll learn how to get information on what Puppet’s doing, when it runs, the changes it makes, how to monitor Puppet, and what to do about many common errors you may encounter.

Summaries
Reports
Dry-run mode
Debug mode
Printing messages
Exec output
Monitoring Puppet
Causes of Puppet run failures
Common Puppet errors and how to fix them

Moving on up

In this chapter you’ll learn some simple principles for writing better Puppet manifests, including style and code layout. You’ll also find out what resources are available for learning more about Puppet, and get some ideas for more advanced projects to build your Puppet knowledge and improve your infrastructure.