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

Working with proxies and jump hosts

Often, when it comes to configuring core network devices, these are isolated from the main network via a proxy or jump host. Ansible lends itself well to automating network device configuration as most of it is performed over SSH; however, this is only helpful in a scenario where Ansible can either be installed and operated from the jump host or, better yet, can operate via a host such as this.

Fortunately, Ansible can do exactly that. Let’s assume that you have two Cumulus Networks switches in your network (these are based on a special distribution of Linux for switching hardware, which is very similar to Debian). These two switches have the cmls01.example.com and cmls02.example.com hostnames, but both can only be accessed from a host called bastion.example.com.

The configuration to support our bastion host is performed in the inventory, rather than in the playbook. We begin by defining an inventory group with the switches in, in the...