Book Image

Mastering Ansible, 4th Edition - Fourth Edition

By : James Freeman, Jesse Keating
Book Image

Mastering Ansible, 4th Edition - Fourth Edition

By: James Freeman, Jesse Keating

Overview of this book

Ansible is a modern, YAML-based automation tool (built on top of Python, one of the world’s most popular programming languages) with a massive and ever-growing user base. Its popularity and Python underpinnings make it essential learning for all in the DevOps space. This fourth edition of Mastering Ansible provides complete coverage of Ansible automation, from the design and architecture of the tool and basic automation with playbooks to writing and debugging your own Python-based extensions. You'll learn how to build automation workflows with Ansible’s extensive built-in library of collections, modules, and plugins. You'll then look at extending the modules and plugins with Python-based code and even build your own collections — ultimately learning how to give back to the Ansible community. By the end of this Ansible book, you'll be confident in all aspects of Ansible automation, from the fundamentals of playbook design to getting under the hood and extending and adapting Ansible to solve new automation challenges.
Table of Contents (18 chapters)
1
Section 1: Ansible Overview and Fundamentals
7
Section 2: Writing and Troubleshooting Ansible Playbooks
13
Section 3: Orchestration with Ansible

Defining a failure

Most modules that ship with Ansible have differing criteria for what constitutes an error. An error condition is highly dependent upon the module and what the module is attempting to accomplish. When a module returns an error, the host will be removed from the set of available hosts, preventing any further tasks or handlers from being executed on that host. Furthermore, the ansible-playbook and ansible executables will exit with a non-zero exit code to indicate failure. However, we are not limited by a module's opinion of what an error is. We can ignore errors or redefine an error condition.

Ignoring errors

A task condition named ignore_errors is used to ignore errors. This condition is a Boolean, meaning that the value should be something Ansible understands to be true, such as yesontrue, or 1 (string or integer).

To demonstrate how to use ignore_errors, let's create...