High Availability Web Application Infrastructure

This Terraform project deploys a highly available web application infrastructure on AWS.

Architecture

• VPC with public subnets across multiple AZs
• Application Load Balancer (ALB)
• Auto Scaling Group (ASG) with EC2 instances
• Security Groups for ALB and EC2 instances

Prerequisites

• Terraform >= 1.0.0
• AWS account and credentials
• AWS CLI configured

Module Structure

.
├── main.tf           # Main configuration file
├── variables.tf      # Input variables
├── outputs.tf        # Output values
├── terraform.tf      # Terraform settings
├── providers.tf      # Provider configurations
├── modules/
│   ├── vpc/         # VPC and networking
│   ├── alb/         # Application Load Balancer
│   └── asg/         # Auto Scaling Group

Usage

1. Initialize Terraform:

terraform init

2. Review the changes:

terraform plan

3. Apply the configuration:

terraform apply

Variables

Name	Description	Type	Default
project_name	Project name prefix	string	"ha-webapp"
vpc_cidr	VPC CIDR block	string	"10.0.0.0/16"
public_subnet_cidrs	Public subnet CIDR blocks	list(string)	["10.0.1.0/24", "10.0.2.0/24"]
instance_type	EC2 instance type	string	"t3.micro"
min_size	Minimum ASG size	number	2
max_size	Maximum ASG size	number	4

Outputs

Name	Description
alb_dns_name	ALB DNS name
asg_name	Auto Scaling Group name