Puppet Cookbook - Third Edition

Puppet Cookbook - Third Edition - Third Edition

Overview of this book

This book is for anyone who builds and administers servers, especially in a web operations context. It requires some experience of Linux systems administration, including familiarity with the command line, file system, and text editing. No programming experience is required.

Preface

What this book covers

What you need for this book

Free Chapter

1. Puppet Language and Style

Introduction

Adding a resource to a node

Using Facter to describe a node

Installing a package before starting a service

Installing, configuring, and starting a service

Using community Puppet style

Creating a manifest

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

Using the future parser

2. Puppet Infrastructure

Introduction

Installing Puppet

Managing your manifests with Git

Creating a decentralized Puppet architecture

Writing a papply script

Running Puppet from cron

Bootstrapping Puppet with bash

Creating a centralized Puppet infrastructure

Creating certificates with multiple DNS names

Running Puppet from passenger

Setting up the environment

Configuring PuppetDB

Configuring Hiera

Setting node-specific data with Hiera

Storing secret data with hiera-gpg

Using MessagePack serialization

Automatic syntax checking with Git hooks

Pushing code around with Git

Managing Environments with Git

3. Writing Better Manifests

Introduction

Using arrays of resources

Using resource defaults

Using defined types

Using tags

Using run stages

Using roles and profiles

Passing parameters to classes

Passing parameters from Hiera

Writing reusable, cross-platform manifests

Getting information about the environment

Importing dynamic information

Passing arguments to shell commands

4. Working with Files and Packages

Introduction

Making quick edits to config files

Editing INI style files with puppetlabs-inifile

Using Augeas to reliably edit config files

Building config files using snippets

Using ERB templates

Using array iteration in templates

Using EPP templates

Using GnuPG to encrypt secrets

Installing packages from a third-party repository

Comparing package versions

5. Users and Virtual Resources

Introduction

Using virtual resources

Managing users with virtual resources

Managing users' SSH access

Managing users' customization files

Using exported resources

6. Managing Resources and Files

Introduction

Distributing cron jobs efficiently

Scheduling when resources are applied

Using host resources

Using exported host resources

Using multiple file sources

Distributing and merging directory trees

Cleaning up old files

Auditing resources

Temporarily disabling resources

7. Managing Applications

Introduction

Using public modules

Managing Apache servers

Creating Apache virtual hosts

Creating nginx virtual hosts

Managing MySQL

Creating databases and users

8. Internode Coordination

Introduction

Managing firewalls with iptables

Building high-availability services using Heartbeat

Managing NFS servers and file shares

Using HAProxy to load-balance multiple web servers

Managing Docker with Puppet

9. External Tools and the Puppet Ecosystem

Introduction

Creating custom facts

Adding external facts

Setting facts as environment variables

Generating manifests with the Puppet resource command

Generating manifests with other tools

Using an external node classifier

Creating your own resource types

Creating your own providers

Creating custom functions

Testing your puppet manifests with rspec-puppet

Using librarian-puppet

Using r10k

10. Monitoring, Reporting, and Troubleshooting

Introduction

Noop – the don't change anything option

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

Managing users with virtual resources

Users are a great example of a resource that may need to be realized by multiple classes. Consider the following situation. To simplify administration of a large number of machines, you defined classes for two kinds of users: developers and sysadmins. All machines need to include sysadmins, but only some machines need developers:

node 'server' { 
  include user::sysadmins 
}

node 'webserver' {
  include user::sysadmins 
  include user::developers 
}

However, some users may be members of both groups. If each group simply declares its members as regular user resources, this will lead to a conflict when a node includes both developers and sysadmins, as in the webserver example.

To avoid this conflict, a common pattern is to make all users virtual resources, defined in a single class user::virtual that every machine includes, and then realizing the users where they are needed. This way, there will be no conflict if a user is a member of multiple groups.

Puppet Cookbook - Third Edition - Third Edition

Puppet Cookbook - Third Edition - Third Edition

Overview of this book

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Puppet Cookbook - Third Edition - Third Edition

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