How to correctly set the id of dynamically created subnets in elb terraform?

Question

Amazon Web Services

How to correctly write the id of the created subnets in elb terraform?

data "aws_availability_zones" "available" {}

locals {
  az_names = data.aws_availability_zones.available.names
}
resource "aws_subnet" "wpl_public_subnet" {
  for_each                = { for index, az_name in local.az_names : index => az_name }
  vpc_id                  = aws_vpc.wpl_vpc.id
  cidr_block              = cidrsubnet(var.vpc_cidr, 8, each.key + 10)
  availability_zone       = local.az_names[each.key]
  map_public_ip_on_launch = true
    tags = {
        Name              = "WPL-PublicSubnet"
        CreatedBy         = var.created_by
    }
}

resource "aws_elb" "wpl_elb" {
  name               = "terraform-elb"
  
  security_groups    = [aws_security_group.wpl_sg.id]
  subnets            = [for_each aws_subnet.wpl_public_subnet : each.value.id]
  

  listener {
    instance_port     = 80
    instance_protocol = "http"
    lb_port           = 80
    lb_protocol       = "http"
  }

  cross_zone_load_balancing   = true
  idle_timeout                = 400
  connection_draining         = true
  connection_draining_timeout = 400

    tags = {
          Name        = "WPL-ELB"
    }
}

I googled and didn't find a good example.

subnets            = [aws_subnet.wpl_public_subnet[*].id]

it doesn't work like that :(

Maybe you need to use aws_subnet.wpl_public_subnet[*].id as a module output and then you can pass it as a list?

Answer 1

subnets = ["${aws_subnet.wpl_public_subnet.*.id}"]