In this chapter, we learned how to manage infrastructure efficiently by using code. We first learned about CloudFormation, a service from AWS that lets you create templates for your different services to describe each AWS component used and its configuration. In order to simplify the creation of those templates, we looked at a couple of options, ranging from CloudFormation Designer, a tool with a GUI, to troposphere, a Python library. After that, we looked at configuration management, one of the most well-known aspects of the DevOps philosophy. To illustrate this topic, we looked at Ansible, one of the most popular configuration management solutions. We first looked at the different ways to use Ansible commands and ran simple commands against our infrastructure. We then looked at how to create playbooks, which allowed us to orchestrate the different steps to deploy our web server. Finally, we looked at how Ansible can be used in pull mode, which usually makes more sense when managing sizable infrastructures.

We now have a good production environment ready to host any application. We have seen how to architect it and monitor our servers. In Chapter 4, Adding Continuous Integration and Continuous Deployment, we will continue to use CloudFormation and Ansible, but in the context of software delivery as we will learn how to put in place continuous integration testing and continuous deployment.