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 host resources


It's not always practical or convenient to use DNS to map your machine names to IP addresses, especially in cloud infrastructures, where those addresses may change all the time. However, if you use entries in the /etc/hosts file instead, you then have the problem of how to distribute those entries to all machines and keep them up to date.

Here's a better way to do it: Puppet's host resource type controls a single /etc/hosts entry, and you can use this to easily map a hostname to an IP address across your whole network. For example, if all your machines need to know the address of the main database server, you can manage it with a host resource.

How to do it...

Follow these steps to create an example host resource:

  1. Modify your site.pp file as follows:
node 'cookbook' {
  host { 'packtpub.com':
    ensure => present,
    ip     => '83.166.169.231',
  }
}
  1. Run Puppet:
[root@cookbook ~]# puppet agent -t
...
/Stage[main]/Main/Node[cookbook]/Host[packtpub.com]/ensure: created...