Puppet 3 Cookbook - Second Edition

Puppet 3 Cookbook - Second Edition

By : John Arundel

Buy this Book

Puppet 3 Cookbook - Second Edition

By: John Arundel

Buy this Book

Overview of this book

A revolution is happening in web operations. Configuration management tools can build servers in seconds, and automate your entire network. Tools like Puppet are essential to taking full advantage of the power of cloud computing, and building reliable, scalable, secure, high-performance systems. More and more systems administration and IT jobs require some knowledge of configuration management, and specifically Puppet."Puppet 3 Cookbook" takes you beyond the basics to explore the full power of Puppet, showing you in detail how to tackle a variety of real-world problems and applications. At every step it shows you exactly what commands you need to type, and includes full code samples for every recipe.The book takes the reader from a basic knowledge of Puppet to a complete and expert understanding of Puppet's latest and most advanced features, community best practices, writing great manifests, scaling and performance, and extending Puppet by adding your own providers and resources. It starts with guidance on how to set up and expand your Puppet infrastructure, then progresses through detailed information on the language and features, external tools, reporting, monitoring, and troubleshooting, and concludes with many specific recipes for managing popular applications.The book includes real examples from production systems and techniques that are in use in some of the world's largest Puppet installations, including a distributed Puppet architecture based on the Git version control system. You'll be introduced to powerful tools that work with Puppet such as Hiera. The book also explains managing Ruby applications and MySQL databases, building web servers, load balancers, high-availability systems with Heartbeat, and many other state-of-the-art techniques

Puppet 3 Cookbook

Credits

About the Author

About the Reviewers

www.PacktPub.com

Preface

Free Chapter

Puppet Infrastructure

Introduction

Installing Puppet

Creating a manifest

Managing your manifests with Git

Creating a decentralized Puppet architecture

Writing a papply script

Running Puppet from cron

Deploying changes with Rake

Bootstrapping Puppet with Rake

Automatic syntax checking with Git hooks

Puppet Language and Style

Introduction

Using community Puppet style

Checking your manifests with puppet-lint

Using modules

Using standard naming conventions

Using inline templates

Iterating over multiple items

Writing powerful conditional statements

Using regular expressions in if statements

Using selectors and case statements

Using the in operator

Using regular expression substitutions

Writing Better Manifests

Introduction

Using arrays of resources

Using node inheritance

Passing parameters to classes

Using class inheritance and overriding

Writing reusable, cross-platform manifests

Getting information about the environment

Importing dynamic information

Passing arguments to shell commands

Working with Files and Packages

Introduction

Making quick edits to config files

Using Augeas to automatically edit config files

Building config files using snippets

Using ERB templates

Using array iteration in templates

Using GnuPG to encrypt secrets

Installing packages from a third-party repository

Building packages automatically from source

Comparing package versions

Users and Virtual Resources

Introduction

Using virtual resources

Managing users with virtual resources

Managing users' SSH access

Managing users' customization files

Efficiently distributing cron jobs

Using schedules to limit when resources can be applied

Using host resources

Using multiple file sources

Distributing directory trees

Cleaning up old files

Auditing resources

Temporarily disabling resources

Applications

Introduction

Managing Apache servers

Creating Apache virtual hosts

Creating Nginx virtual hosts

Managing MySQL

Managing Ruby

Servers and Cloud Infrastructure

Introduction

Building high-availability services using Heartbeat

Managing NFS servers and file shares

Using HAProxy to load-balance multiple web servers

Managing firewalls with iptables

Managing EC2 instances

Managing virtual machines with Vagrant

External Tools and the Puppet Ecosystem

Introduction

Creating custom facts

Adding external facts

Setting facts as environment variables

Importing configuration data with Hiera

Storing secret data with hiera-gpg

Generating manifests with puppet resource

Generating manifests with other tools

Testing your manifests with rspec-puppet

Using public modules

Using an external node classifier

Creating your own resource types

Creating your own providers

Creating your own functions

Monitoring, Reporting, and Troubleshooting

Introduction

Doing a dry run

Logging command output

Logging debug messages

Generating reports

Producing automatic HTML documentation

Drawing dependency graphs

Understanding Puppet errors

Inspecting configuration settings

Index

Customer Reviews

5 star

4 star

3 star

2 star

1 star

Doing a dry run

Sometimes your Puppet manifest doesn't do exactly what you expected, or perhaps someone else has checked in changes you didn't know about. Either way, it's good to know exactly what Puppet is going to do before it does it.

If it would update a config file and restart a production service, for example, this could result in unplanned downtime. Also, sometimes manual configuration changes are made on a server which Puppet would overwrite.

To avoid these problems, you can use Puppet's dry run mode (also called noop mode, for no operation).

How to do it…

Follow this step in order to do a dry run with Puppet. Run Puppet (or the papply script we wrote in Chapter 1, Puppet Infrastructure) with the --noop switch. The output will depend on whether Puppet has any changes to make to the machine. If there are resources to be applied, you'll see output similar to this (not the same, of course; the actual output will depend on your manifest):

ubuntu@cookbook:~/puppet$ papply --noop
Notice:...

Puppet 3 Cookbook - Second Edition

By : John Arundel

Puppet 3 Cookbook - Second Edition

By: John Arundel

Overview of this book

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Current Title:

Puppet 3 Cookbook - Second Edition

Doing a dry run

How to do it…