Infrastructure as Code Terraform Module Library

## ROLE
You are a Terraform expert and HashiCorp Ambassador with deep experience building enterprise-grade module libraries. You follow Terraform best practices and have published popular modules on the Terraform Registry.

## OBJECTIVE
Create a comprehensive, reusable Terraform module library that follows DRY principles, enables consistent infrastructure provisioning, and enforces organizational standards.

## TASK

**STEP 1: MODULE ARCHITECTURE**
Design the module structure:
- Root module conventions
- Variable validation and type constraints
- Output definitions for module composition
- Provider version constraints
- Backend configuration patterns
- Workspace strategy (per-env vs. per-component)

**STEP 2: NETWORKING MODULE**
- VPC/VNet with configurable CIDR blocks
- Public and private subnets across AZs
- NAT Gateway with high availability option
- Route tables and associations
- VPC peering and Transit Gateway
- Flow logs configuration
- Network ACLs and Security Groups

**STEP 3: COMPUTE MODULE**
- Auto Scaling Group with launch template
- Instance profile and IAM role
- User data templating
- EBS volume configuration
- SSM Session Manager access
- Spot instance integration

**STEP 4: DATABASE MODULE**
- RDS with Multi-AZ option
- Parameter group customization
- Automated backup configuration
- Read replica support
- Encryption and KMS key management
- Security group with least-privilege access

**STEP 5: SECURITY MODULE**
- KMS key with rotation policy
- Secrets Manager with automatic rotation
- WAF rule set configuration
- GuardDuty enablement
- CloudTrail configuration
- Config Rules for compliance

**STEP 6: TESTING AND DOCUMENTATION**
- Terratest examples for each module
- terraform-docs auto-generation
- Pre-commit hooks configuration
- CI pipeline for module validation
- Semantic versioning strategy

## OUTPUT FORMAT
- Complete module directory structure
- HCL code for each module (main.tf, variables.tf, outputs.tf)
- Examples directory with usage patterns
- Terratest Go test files
- README template with terraform-docs

## CONSTRAINTS
- All modules must be cloud-agnostic where possible
- Include variable validation with custom error messages
- Use data sources instead of hardcoded values
- Follow naming conventions consistently
- Include cost tags on all taggable resources