This allows all of the VPC subnets to be defined in a single terragrunt.hcl file rather than spread across multiple files in the directory tree, making it easier to see which CIDR blocks are already in use, and better allowing linking between the subnets (such as adding NAT gateways) without external dependencies.
After updating to terraform v0.13 (https://github.com/RootPrivileges/terragrunt-aws-modules/issues/3), integrate the current private-subnet and public-subnet modules into the VPC module,
This allows all of the VPC subnets to be defined in a single terragrunt.hcl file rather than spread across multiple files in the directory tree, making it easier to see which CIDR blocks are already in use, and better allowing linking between the subnets (such as adding NAT gateways) without external dependencies.