terraform

test.tf

data "external" "generate_priority_80" {
  program = [
    "python3",
    "${path.module}/../helpers/alb_priority/generate_priority.py"]
  query {
    listener_arn = "${aws_alb_listener.test123-listener-80.arn}"
    region = "eu-central-1"
    component = "${aws_alb_listener_rule.test_rule_80.arn}"
  }
}

resource "aws_alb" "test123" {
  name = "resheftest123"
  internal = true
  security_groups = ["sg-blat"]
  subnets = ["subnet-blat", "subnet-blat2"]
  idle_timeout = 3600
}

resource "aws_alb_listener" "test123-listener-80" {
  load_balancer_arn = "${aws_alb.test123.arn}"
  port = "80"
  protocol = "HTTP"

  default_action {
    target_group_arn = "some-arn"
    type = "forward"
  }
}

resource "aws_alb_listener_rule" "test_rule_80" {

  listener_arn = "${aws_alb_listener.test123-listener-80.arn}"
  priority = "${data.external.generate_priority_80.result["priority"]}"

  action {
    type = "forward"
    target_group_arn = "some-arn"
  }

  condition {
    field = "host-header"
    values = [
      "test.test.test"]
  }
}