Book Image

Practical Ansible - Second Edition

By : James Freeman, Fabio Alessandro Locati, Daniel Oh
Book Image

Practical Ansible - Second Edition

By: James Freeman, Fabio Alessandro Locati, Daniel Oh

Overview of this book

Ansible empowers you to automate a myriad of tasks, including software provisioning, configuration management, infrastructure deployment, and application rollouts. It can be used as a deployment tool as well as an orchestration tool. While Ansible provides simple yet powerful features to automate multi-layer environments using agentless communication, it can also solve other critical IT challenges, such as ensuring continuous integration and continuous deployment (CI/CD) with zero downtime. In this book, you'll work with the latest release of Ansible and learn how to solve complex issues quickly with the help of task-oriented scenarios. You'll start by installing and configuring Ansible on Linux and macOS to automate monotonous and repetitive IT tasks and learn concepts such as playbooks, inventories, and roles. As you progress, you'll gain insight into the YAML syntax and learn how to port between Ansible versions. Additionally, you'll understand how Ansible enables you to orchestrate multi-layer environments such as networks, containers, and the cloud. By the end of this Ansible book, you'll be well versed in writing playbooks and other related Ansible code to overcome all your IT challenges, from infrastructure-as-a-code provisioning to application deployments and handling mundane day-to-day maintenance tasks.
Table of Contents (21 chapters)
Free Chapter
1
Part 1:Learning the Fundamentals of Ansible
6
Part 2:Expanding the Capabilities of Ansible
12
Part 3:Using Ansible in an Enterprise

Configuring play execution via strategies

As your playbooks become increasingly complex, it becomes more and more important that you have robust ways to debug any issues that might arise. For example, is there a way you can check the contents of a given variable (or variables) during execution without the need to insert ansible.builtin.debug statements throughout your playbook? Similarly, we have so far seen that Ansible will ensure that a particular task runs to completion on all inventory hosts that it applies to before moving on to the next task – is there a way to vary this?

When you get started with Ansible, the execution strategy that you see by default (and we have seen this so far in every playbook we have executed, even though we have not mentioned it by name) is known as linear. This does exactly what it describes – each task is executed in turn on all applicable hosts before the next task is started. However, there is another less commonly used strategy...