In this chapter, we learned how to efficiently manage infrastructure by using code. We also explored CloudFormation, an AWS service that allows you to create templates for your different services in order to describe each AWS component used, as well as 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 graphic user interface, 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 infrastructure.

We now have a good production environment that is ready to host any application, and we have seen how to architect it and monitor our servers. In Chapter 5, Adding Continuous Integration and Continuous Deployment, we will continue to use CloudFormation and Ansible, but in the context of software delivery: we will learn how to put in place continuous integration testing and continuous deployment.