Terraform nat gateway AWS - amazon-web-services

Question

I am trying to create nat gateway from terraform by using AWS as provider but subnet_id in resource aws_nat_gateway always gives me error. I am trying to assign public subnet in subnet_id on resource "aws_nat_gateway" "sample_nat_gateway" from variables.tf file but failing in doing so and need support if someone can assist ?
Below is my vpc.tf file of vpc module
resource "aws_subnet" "public-subnet" {
for_each = var.prefix
availability_zone_id = each.value["az"]
cidr_block = each.value["cidr"]
vpc_id = aws_vpc.sample_vpc.id
tags = {
Name = "${var.name}-${each.value["az"]}"
}
}
resource "aws_nat_gateway" "sample_nat_gateway" {
allocation_id = aws_eip.sample_eip.id
subnet_id = ""
tags = {
Name = "${var.name}-sample-nat-gateway"
Environment = var.environment
}
depends_on = [aws_internet_gateway.sample_igw]
}
variables.tf
variable "prefix" {
type = map
default = {
sub-1 = {
az = "use2-az1"
cidr = "10.0.1.0/16"
}
sub-2 = {
az = "use2-az2"
cidr = "10.0.2.0/24"
}
}
}

Answer 1

Subent's can't be empty You have to provide valid subnet id where the NAT is going to be placed. For example:
resource "aws_nat_gateway" "sample_nat_gateway" {
allocation_id = aws_eip.sample_eip.id
subnet_id = aws_subnet.public-subnet["sub-1"].id
tags = {
Name = "${var.name}-sample-nat-gateway"
Environment = var.environment
}
depends_on = [aws_internet_gateway.sample_igw]
}
where aws_subnet.example is one of the public subnets in your VPC.