- 테라폼으로 rds(postgres) 생성
- RDS 컨셉: https://stackoverflow.com/questions/49642056/rds-cluster-and-db-instance-concept
- https://isc9511.tistory.com/167
- https://codepal.ai/terraform-writer/query/2dxjCP3P/terraform-module-rds-cluster-variables-agnostic
- https://msameeduddin.medium.com/using-terraform-deploying-postgresql-instance-with-read-replica-in-aws-49e75012c0b3