AWS Terraform Module Patterns

VPC Module

• VPC with public/private subnets
• Internet Gateway and NAT Gateways
• Route tables and associations
• Network ACLs
• VPC Flow Logs

EKS Module

• EKS cluster with managed node groups
• IRSA (IAM Roles for Service Accounts)
• Cluster autoscaler
• VPC CNI configuration
• Cluster logging

RDS Module

• RDS instance or cluster
• Automated backups
• Read replicas
• Parameter groups
• Subnet groups
• Security groups

S3 Module

• S3 bucket with versioning
• Encryption at rest
• Bucket policies
• Lifecycle rules
• Replication configuration

ALB Module

• Application Load Balancer
• Target groups
• Listener rules
• SSL/TLS certificates
• Access logs

Lambda Module

• Lambda function
• IAM execution role
• CloudWatch Logs
• Environment variables
• VPC configuration (optional)

Security Group Module

• Reusable security group rules
• Ingress/egress rules
• Dynamic rule creation
• Rule descriptions

Best Practices

1. Use AWS provider version ~> 5.0
2. Enable encryption by default
3. Use least-privilege IAM
4. Tag all resources consistently
5. Enable logging and monitoring
6. Use KMS for encryption
7. Implement backup strategies
8. Use PrivateLink when possible
9. Enable GuardDuty/SecurityHub
10. Follow AWS Well-Architected Framework