Example code for vpc.id problem

modules|services|netbox|main.tf

module "security_groups" {
  source     = "./modules/security_groups"
  db_port    = "${var.db_port}"
  identifier = "${local.identifier}"
  vpc_id     = "${var.vpc_id}"
}

modules|vpc|main.tf

resource "aws_vpc" "vpc" {
  cidr_block = "${var.cidr_block}"

  tags = {
    Name = "${var.name}"
  }
}

output "vpc_id" {
  value = "${aws_vpc.vpc.id}"
}

profiles|profile_netbox|main.tf

data "terraform_remote_state" "vpc" {
  backend = "s3"

  config {
    bucket = "${var.terraform_state_bucket}"
    key    = "${var.vpc_state_path}"
    region = "${var.terraform_state_region}"
  }
}

module "netbox" {
  source = "git@github.com:acme/terraform.git//modules/services/netbox"

  site  = "${var.site}"
  stage = "${var.stage}"

  vpc_id = "${data.terraform_remote_state.vpc.vpc_id}"

  db_password   = "${var.db_password}"
  db_subnet_ids = "${data.terraform_remote_state.vpc.private_subnet_ids}"
}

profiles|profile_vpc|main.tf

module "vpc" {
  source     = "git@github.com:acme/terraform.git//modules/vpc"
  cidr_block = "${lookup(local.vpc_data[var.vpc_key], "cidr_block")}"
  name       = "${lookup(local.vpc_data[var.vpc_key], "name")}"
}
  
output "vpc_id" {
  value = "${module.vpc.vpc_id}"
}