In this article, by Jonathan McAllister, author of the book, Implementing DevOps with Ansible 2, we will learn what is Ansible, how users can leverage it, it's architecture, the key differentiators of Ansible from other configuration managements. We will also see the organizations that were successfully able to leverage Ansible.

(For more resources related to this topic, see here.)

What is Ansible?

Ansible is a relatively new addition to the DevOps and configuration management space. It's simplicity, structured automation format and development paradigm have caught the eyes of both small and large corporations alike. Organizations as large as Twitter have managed successfully to leverage Ansible for highly scaled deployments and configuration management across implementations across thousands of servers simultaneously. And Twitter isn't the only organization that has managed to implement Ansible at scale, other well-known organizations that have successfully leveraged Ansible include Logitech, NASA, NEC, Twitter, Microsoft and hundreds more. As it stands today, Ansible is in use by major players around the world managing thousands of deployments and configuration management solutions world wide.

The Ansible's Automation Architecture

Ansible was created with an incredibly flexible and scalable automation engine. It allows users to leverage it in many diverse ways and can be conformed to be used in the way that best suits your specific needs. Since Ansible is agentless (meaning there is no permanently running daemon on the systems it manages or executes from), it can be used locally to control a single system (without any network connectivity), or leveraged to orchestrate and execute automation against many systems, via a control server. In addition to the aforementioned named architectures, Ansible can also be leveraged via Vagrant or Docker to provision infrastructure automatically. This type of solution basically allows the Ansible user to bootstrap their hardware or infrastructure provisioning by running an Ansible playbook(s).

If you happen to be a Vagrant user, there is instructions within the HashiCorp Ansible provisioning located at https://www.vagrantup.com/docs/provisioning/ansible.html.

Ansible is open source, module based, pluggable, and agentless. These key differentiators from other configuration management solutions give Ansible a significant edge. Let's take a look at each of these differentiators in details and see what that actually means for Ansible developers and users:

Open source:

It is no secret that successful open source solutions are usually extraordinarily feature rich. This is because instead of a simple 8 person (or even 100) person engineering team, there are potentially thousands of developers. Each development and enhancement has been designed to fit a unique need. As a result the end deliverable product provides the consumers of Ansible with a very well rounded solution that can be adapted or leveraged in numerous ways.

Module based:

Ansible has been developed with the intention to integrate with numerous other open and closed source software solutions. This idea means that Ansible is currently compatible with multiple flavors of Linux, Windows and Cloud providers. Aside from its OS level support Ansible currently integrates with hundreds of other software solutions; including EC2, Jira, Jenkins, Bamboo, Microsoft Azure, Digital Ocean, Docker, Google and MANY MANY more.

For a complete list of Ansible modules, please consult the Ansible official module support list located at http://docs.ansible.com/ansible/modules_by_category.html.

Agentless:

One of the key differentiators that gives Ansible an edge against the competition is the fact that it is 100% agentless. This means there are no daemons that need to be installed on remote machines, no firewall ports that need to be opened (besides traditional SSH), no monitoring that needs to be performed on the remote machines and no management that needs to be performed on the infrastructure fleet. In effect, this makes Ansible very self sufficient.

Since Ansible can be implemented in a few different ways the aim of this section is to highlight these options and help get us familiar with the architecture types that Ansible supports. Generally the architecture of Ansible can be categorized into three distinct architecture types. These are described next.

Pluggable:

While Ansible comes out of the box with a wide spectrum of software integrations support, it is often times a requirement to integrate the solution with a company based internal software solution or a software solution that has not already been integrated into Ansible's robust playbook suite. The answer to such a requirement would be to create a plugin based solution for Ansible, this providing the custom functionality necessary.

Summary

In this article, we discussed the architecture of Ansible, the key differentiators that differentiate Ansible from other configuration management. We learnt that Ansible can also be leveraged via Vagrant or Docker to provision infrastructure automatically. We also saw that Ansible has been successfully leveraged by large oraganizations like Twitter, Microsoft, and many more.