4 Deploying a multi-tiered web application in AWS

Highly available, scalable web hosting has been a complex and expensive proposition until relatively recently. It wasn’t until AWS released its Elastic Compute Cloud (EC2) service in 2006 that things started changing for the better. EC2 was the first pay-as-you-go service that enabled customers to provision to nearly infinite capacity on demand. As great as EC2 was, a significant tooling gap existed that could not be met with CloudFormation or existing configuration management tools. Terraform was designed to fill the tooling gap, and we are now going to look at how Terraform solves this problem. In this chapter, we deploy a highly available and scalable multi-tiered web application in AWS.

4.1 Architecture

4.2 Terraform modules

4.2.1 Module syntax

4.2.2 What is the root module?

4.2.3 Standard module structure

4.3 Root module

4.3.1 Code

4.4 Networking module

4.5 Database module

4.5.1 Passing data from the networking module

4.5.2 Generating a random password

4.6 Autoscaling module

4.6.1 Trickling down data

4.6.2 Templating a cloudinit_config

4.7 Deploying the web application

4.8 Fireside chat

Summary