AWS Ruby Application Infrastructure

Introduction

This project demonstrates enterprise-grade Infrastructure as Code (IaC) for deploying a production-ready Ruby application on AWS. It showcases a well-architected, modular Terraform configuration that provisions a complete cloud infrastructure with high availability, security, and scalability as core design principles.

The infrastructure is designed to support a containerized Ruby application running behind a load balancer, with a managed PostgreSQL database, all within an isolated VPC environment. The configuration follows AWS Well-Architected Framework principles and Terraform best practices to ensure maintainability, reusability, and operational excellence.

Overview

This project provisions a complete AWS infrastructure including:

• Custom VPC with public subnets and Internet Gateway
• RDS PostgreSQL database with multi-AZ support
• Auto Scaling Group with EC2 instances for the Ruby application
• Application Load Balancer for traffic distribution
• IAM roles for EC2 with ECR and S3 access
• Security Groups for network isolation

Architecture

Internet → ALB → EC2 Auto Scaling Group (Ruby App) → RDS PostgreSQL

Modules

• modules/vpc - VPC, subnets, security groups, and routing
• modules/ec2 - Launch template, ASG, ALB, and target groups

Best Practices Implemented

1. Modular Architecture

• Infrastructure split into reusable modules (vpc, ec2) for better organization and maintainability
• Each module has clear inputs/outputs and handles specific infrastructure concerns
• Promotes code reusability across different environments

2. Security First

• IAM Least Privilege: EC2 instances use IAM roles with read-only access to ECR and S3
• Network Isolation: Resources deployed in custom VPC with security groups controlling traffic
• Defense in Depth: Multiple security layers (VPC, Security Groups, IAM)
• Database deployed in private subnets with restricted security group rules

3. High Availability & Resilience

• Multi-AZ RDS: Database configured with Multi-AZ for automatic failover
• Auto Scaling Group: Application scales horizontally based on demand
• Load Balancing: ALB distributes traffic across multiple availability zones
• EC2 instances deployed across multiple subnets for fault tolerance

4. Infrastructure as Code Principles

• Parameterization: All configurations externalized via variables in terraform.tfvars
• DRY Principle: Use of for_each loops to avoid code duplication
• Data Sources: Leverages data blocks for dynamic policy generation
• Explicit Dependencies: Clear depends_on declarations for proper resource ordering

5. Automation & DevOps

• User data scripts automate EC2 configuration (Docker installation)
• Launch templates ensure consistent instance configuration
• Infrastructure provisioning is fully automated and repeatable

Notes

• RDS skip_final_snapshot is enabled for development purposes
• EC2 instances are configured with Docker via user data script