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

Setting OS and distribution variances

As stated earlier, our goal is to try to use the same automation code as widely as possible. However, as much as we try to standardize our technology environments, variants always creep in. For example, it is impossible to simultaneously perform a major upgrade on all your servers in one go, so when a major new OS version comes out, such as Red Hat Enterprise Linux (RHEL) 8 or Ubuntu Server 20.04, it is inevitable that some machines will remain on older versions as others are upgraded. Similarly, an environment might be standardized on Ubuntu, but then an application is introduced that has only been certified to run on CentOS. In short, as important as standardization is, variances will always creep in.

When writing Ansible playbooks, especially roles, your goal should be for them to be as widely applicable as possible throughout your environment. A classic example of this is package management—let’s say you are writing a role...