Building a Two-Tier AWS Infrastructure with Terraform, Flask & Ansible — Every File Explained

Introduction A two-tier architecture on AWS — the bread and butter of real-world cloud deployments. Here's the idea: Tier 1 (Public) : An EC2 instance sitting in a public subnet, running a Flask web application. This is what users hit. Tier 2 (Private) : An RDS MySQL database sitting in private subnets. No direct internet access. Only the EC2 instance can talk to it. The infrastructure is provisioned with Terraform (modularized), the app is deployed with Ansible, and the application itself is a