Nested for in locals for maps remapping

Terraform
1

Hello,

I’m a newbie in terraform and want to realize vpc module with a configuration like shown below.

For now, the output looks like I expected, then I want to iterate over the local variable for creating subnets and all other necessary resources, but I doubt about this approach is correct and not overengineered.
So it would be perfect to hear the opinions from skilled terraformers.

variable "vpcs" {
  type = map
  default = {
    vpc1 = {
       cidr            = "172.22.0.0/16",
       private_subnets = ["172.22.1.0/24", "172.22.2.0/24"],
       public_subnets  = ["172.22.10.0/24", "172.22.20.0/24"],
       tags            = {
                          Name = "app-vpc1",
                          Environment = "production",
                          Terraform = "True"
                         }
    },
    vpc2 = {
      cidr             = "172.12.0.0/16",
      private_subnets  = ["172.12.1.0/24", "172.12.2.0/24"],
      public_subnets   = ["172.12.10.0/24", "172.12.20.0/24"],
      tags             = {
                          Name = "app-vpc2",
                          Environment = "production",
                          Terraform = "True"
                         }
    }
  }
}

and my module:

variable "vpcs" {
  type       = map
}

locals {
  nestedforeach = [
    for vpc_name, vpc_config in var.vpcs: [
      for public_subnet in vpc_config.public_subnets: {"${public_subnet}": aws_vpc.this[vpc_name].id}
    ]
  ]
}

resource "aws_vpc" "this" {
  for_each             = var.vpcs

  cidr_block           = each.value.cidr
  instance_tenancy     = "default"
  enable_dns_support   = "true"
  enable_dns_hostnames = "true"
  enable_classiclink   = "false"

  tags = each.value.tags
}

output test {
  value = flatten(local.nestedforeach)
}

Output:

module.kilda-vpc.aws_vpc.this["vpc1"]: Refreshing state... [id=vpc-082108b97c66df36b]
module.kilda-vpc.aws_vpc.this["vpc2"]: Refreshing state... [id=vpc-0a5a4cbc58f9dc664]

Outputs:

test = [
  {
    "172.22.10.0/24" = "vpc-082108b97c66df36b"
  },
  {
    "172.22.20.0/24" = "vpc-082108b97c66df36b"
  },
  {
    "172.12.10.0/24" = "vpc-0a5a4cbc58f9dc664"
  },
  {
    "172.12.20.0/24" = "vpc-0a5a4cbc58f9dc664"
  },
]