Book Image

Puppet 4 Essentials, Second Edition - Second Edition

By : Felix Frank, Martin Alfke
Book Image

Puppet 4 Essentials, Second Edition - Second Edition

By: Felix Frank, Martin Alfke

Overview of this book

Puppet is a configuration management tool that allows you to automate all your IT configurations, giving you control over what you do to each Puppet Agent in a network, and when and how you do it. In this age of digital delivery and ubiquitous Internet presence, it's becoming increasingly important to implement scalable and portable solutions, not only in terms of software, but also the systems that run it. The free Ruby-based tool Puppet has established itself as the most successful solution to manage any IT infrastructure. Ranging from local development environments through complex data center setups to scalable cloud implementations, Puppet allows you to handle them all with a unified approach. Puppet 4 Essentials, Second Edition gets you started rapidly and intuitively as you’ll put Puppet’s tools to work right away. It will also highlight the changes associated with performance improvements as well as the new language features in Puppet 4. We’ll start with a quick introduction to Puppet to get you managing your IT systems quickly. You will then learn about the Puppet Agent that comes with an all-in-one (AIO) package and can run on multiple systems. Next, we’ll show you the Puppet Server for high-performance communication and passenger packages. As you progress through the book, the innovative structure and approach of Puppet will be explained with powerful use cases. The difficulties that are inherent to a complex and powerful tool will no longer be a problem for you as you discover Puppet's fascinating intricacies. By the end of the book, you will not only know how to use Puppet, but also its companion tools Facter and Hiera, and will be able to leverage the flexibility and expressive power implemented by their tool chain.
Table of Contents (15 chapters)
Puppet 4 Essentials Second Edition
Credits
About the Authors
About the Reviewer
www.PacktPub.com
Preface
Index

Overriding resource parameters


Both exported and virtual resources are declared once, and are then collected in different contexts. The syntax is very similar, as are the concepts.

Sometimes, a central definition of a resource cannot be safely realized on all of your nodes, though; for example, consider the set of all your user resources. You will most likely wish to manage the user ID that is assigned to each account in order to make them consistent across your networks.

Tip

This is often solved through LDAP or similar directories, but that is not possible for some sites.

Even if all accounts on almost all machines will be able to use their designated ID, there are likely to be some exceptions. On a few older machines, some IDs are probably being used for other purposes already, which cannot be changed easily. On such machines, creating users with these IDs will fail.

Tip

The accounts can be created if duplicate IDs are allowed, but that is not a solution to this problem—duplicates are usually...