I have a variable with a list of load-balancer targets. Ports, healthchecks etc. Defined as follows (with some sane defaults):

variable "port_mappings" {
  type = list(object({
    containerPort = string
    hostPort = string
    lbPort = string
    host_tls = bool
    lb_tls = bool
    health_path = string
    health_interval = number
    unhealthy_threshold = number
    health_matcher = string
    create_before_destroy = bool
  }))
  default = [{
    containerPort = "8080"
    hostPort = "8080"
    lbPort = "443"
    host_tls = true
    lb_tls = true
    health_path = "/health"
    health_interval = 30
    unhealthy_threshold = 5
    health_matcher = "200-399"
    create_before_destroy = true
  }]
}

I then use that list of objects to create a list of resources like so:

resource "aws_lb_target_group" "this" {
  for_each    = var.port_mappings
  name        = "${var.environment}-${var.app_name}-http-${each.value.hostPort}"
  vpc_id      = var.vpc_id
  protocol    = "TCP"
  port        = each.value.hostPort
  target_type = "ip"

  health_check {
    port                = "traffic-port"
    protocol            = each.value.host_tls ? "HTTPS" : "HTTP"
    path                = each.value.health_path
    interval            = each.value.health_interval
    unhealthy_threshold = each.value.unhealthy_threshold
    matcher             = each.value.health_matcher
  }

  lifecycle {
    create_before_destroy = each.value.create_before_destroy
  }
}

Next, I want to create an “aws_lb_listener” resource for each “aws_lb_target_group”, but I need value from both the list of objects (my var) and the list of “aws_lb_target_group” resources.

resource "aws_lb_listener" "this" {
  for_each = aws_lb_target_group.this
  load_balancer_arn = aws_lb.this.arn
  port              = **lbPort value from my list of objects var**
  protocol          = **ternary based on lb_tls bool from my list of objects var**
  certificate_arn   = aws_acm_certificate.this.arn

  default_action {
    type             = "forward"
    target_group_arn = **target group from the list of aws_lb_target_group resources**
  }
}

What’s the best way to go about this?