Web Application Template

A production-ready template for web applications with load balancing, auto-scaling, and database.

Overview

This template provisions a complete web application stack:

• Application Load Balancer (ALB) - Load balancing and SSL termination
• Auto Scaling Group (ASG) - Auto-scaling EC2 instances
• RDS Database - Managed database (MySQL or PostgreSQL)
• Security Groups - Network security
• CloudWatch - Monitoring and logging

Architecture

Internet
    │
    ▼
┌──────────────┐
│      ALB     │ (Application Load Balancer)
└──────┬───────┘
       │
       ▼
┌──────────────┐
│      ASG     │ (Auto Scaling Group)
│  EC2 Instances│
└──────┬───────┘
       │
       ▼
┌──────────────┐
│     RDS      │ (Database)
└──────────────┘

Parameters

Parameter	Type	Required	Default	Description
app_name	string	Yes	-	Application name
environment	string	Yes	-	Environment (dev/staging/prod)
instance_type	string	No	t3.medium	EC2 instance type
min_size	number	No	2	Minimum instances
max_size	number	No	10	Maximum instances
desired_capacity	number	No	2	Desired instances
db_instance_class	string	No	db.t3.micro	RDS instance class
db_engine	string	No	mysql	Database engine (mysql/postgres)
db_allocated_storage	number	No	20	Database storage (GB)

Usage

Via Portal

1. Select "Web Application" from catalog
2. Fill in parameters
3. Review configuration
4. Click "Provision"

Via Terraform

module "web_app" {
  source = "./service-catalog/web-app"
  
  app_name     = "my-web-app"
  environment  = "dev"
  instance_type = "t3.medium"
  min_size     = 2
  max_size     = 10
}

Outputs

• alb_dns_name - ALB DNS name for accessing the application
• rds_endpoint - RDS database endpoint
• security_group_id - Security group ID
• asg_name - Auto Scaling Group name

Cost Estimate

Monthly Cost (dev environment):

• ALB: ~$16/month
• EC2 (2x t3.medium): ~$60/month
• RDS (db.t3.micro): ~$15/month
• Total: ~$91/month

Cost to Complete (run for 3-4 hours): ~$5-10

Security Features

• SSL/TLS termination at ALB
• Security groups with least privilege
• RDS encryption at rest
• VPC isolation
• CloudWatch logging

Monitoring

• CloudWatch metrics for ALB, ASG, and RDS
• Auto-scaling based on CPU/memory
• Health checks for instances
• Database monitoring

Best Practices

1. Use Multiple AZs: Deploy across availability zones
2. Enable Auto-Scaling: Handle traffic spikes
3. Monitor Costs: Set up budget alerts
4. Regular Backups: Enable RDS automated backups
5. Update Regularly: Keep AMIs and database updated