terraform/examples/aws-networking/region/subnets.tf

data "aws_availability_zones" "all" {
}

module "primary_subnet" {
  source            = "../subnet"
  vpc_id            = "${aws_vpc.main.id}"
  availability_zone = "${data.aws_availability_zones.all.names[0]}"
}

module "secondary_subnet" {
  source            = "../subnet"
  vpc_id            = "${aws_vpc.main.id}"
  availability_zone = "${data.aws_availability_zones.all.names[1]}"
}