Book Image

Mastering Ansible. - Third Edition

By : James Freeman, Jesse Keating
Book Image

Mastering Ansible. - Third Edition

By: James Freeman, Jesse Keating

Overview of this book

Automation is essential for success in the modern world of DevOps. Ansible provides a simple, yet powerful, automation engine for tackling complex automation challenges. This book will take you on a journey that will help you exploit the latest version's advanced features to help you increase efficiency and accomplish complex orchestrations. This book will help you understand how Ansible 2.7 works at a fundamental level and will also teach you to leverage its advanced capabilities. Throughout this book, you will learn how to encrypt Ansible content at rest and decrypt data at runtime. Next, this book will act as an ideal resource to help you master the advanced features and capabilities required to tackle complex automation challenges. Later, it will walk you through workflows, use cases, orchestrations, troubleshooting, and Ansible extensions. Lastly, you will examine and debug Ansible operations, helping you to understand and resolve issues. By the end of the book, you will be able to unlock the true power of the Ansible automation engine and tackle complex, real- world actions with ease.
Table of Contents (17 chapters)
Free Chapter
1
Section 1: Ansible Overview and Fundamentals
6
Section 2: Writing and Troubleshooting Ansible Playbooks
12
Section 3: Orchestration with Ansible

Comparing values

Comparisons are used in many places with Ansible. Task conditionals are comparisons. Jinja2 control structures such as if/elif/else blocks, for loops, and macros often use comparisons; some filters use comparisons as well. To master Ansible's usage of Jinja2, it is important to understand what comparisons are available.

Comparisons

Like most languages, Jinja2 comes equipped with the standard set of comparison expressions you would expect, which will render a Boolean true or false.

The expressions in Jinja2 are as follows:

Expression Definition
== True if two objects are equal
!= True if two objects are not equal
> True if the left-hand side is greater than the right-hand side
< True if...