In previous releases of Puppet, variables were not typed. A variable could hold any sort of value. Although this makes writing code somewhat easier, it leads to many problems. Variables that expect an array could be passed a string; variables that expect an integer may be passed a String. Type mismatch can have very bad affects so, to combat this problem, several helper functions were created in stdlib
to validate the type of a variable. The validation functions were named for the data type they validated and included validate_array
, validate_hash
, validate_numeric
, and validate_string
. All these functions have been deprecated in Puppet 5 and replaced with the assert_type
function. The assert_type
function can be used to ensure that a variable is of any given type. Puppet5 also enforces types when they are assigned to class parameters, as we'll see in the next section.
Puppet 5 Cookbook - Fourth Edition
By :
Puppet 5 Cookbook - Fourth Edition
By:
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
Free Chapter
Puppet Language and Style
Puppet Infrastructure
Writing Better Manifests
Working with Files and Packages
Users and Virtual Resources
Managing Resources and Files
Managing Applications
Servers and Cloud Infrastructure
External Tools and the Puppet Ecosystem
Monitoring, Reporting, and Troubleshooting
Other Books You May Enjoy
Index
Customer Reviews