Book Image

Puppet 5 Cookbook - Fourth Edition

By : Thomas Uphill
Book Image

Puppet 5 Cookbook - Fourth Edition

By: Thomas Uphill

Overview of this book

Puppet is a configuration management system that automates all your IT configurations, giving you control of managing each node. Puppet 5 Cookbook will take you through Puppet's latest and most advanced features, including Docker containers, Hiera, and AWS Cloud Orchestration. Updated with the latest advancements and best practices, this book delves into various aspects of writing good Puppet code, which includes using Puppet community style, checking your manifests with puppet-lint, and learning community best practices with an emphasis on real-world implementation. You will learn to set up, install, and create your first manifests with version control, and also learn about various sysadmin tasks, including managing configuration files, using Augeas, and generating files from snippets and templates. As the book progresses, you'll explore virtual resources and use Puppet's resource scheduling and auditing features. In the concluding chapters, you'll walk through managing applications and writing your own resource types, providers, and external node classifiers. By the end of this book, you will have learned to report, log, and debug your system.
Table of Contents (16 chapters)
Title Page
Packt Upsell
Contributors
Preface
Index

Using exported host resources


In the previous example, we used the spaceship syntax to collect virtual host resources for hosts of type database or hosts of type web. You can use the same trick with exported resources. The advantage of using exported resources is that as you add more database servers, the collector syntax will automatically pull in the newly created exported host entries for those servers. This makes your /etc/hosts entries more dynamic.

Getting ready

We will be using exported resources. If you haven't already done so, set up puppetdb and enable storeconfigs to use puppetdb as outlined in Chapter 2, Puppet Infrastructure.

How to do it...

In this example, we will configure database servers and clients to communicate with each other. We'll make use of exported resources to do the configuration:

  1. Create a new database module, db:
t@mylaptop ~/puppet/modules $ mkdir -p db/manifests/
  1. Create a new class for your database servers, db::server:
class db::server {
  @@host {"$::fqdn":
   ...