Terraform - create ALB

# Create the ALB
resource "aws_alb" "nexus_alb" {
  name = "nexus-alb"
  internal = true
  load_balancer_type = "application"
  security_groups = ["${aws_security_group.alb.id}"]
  subnets = ["${data.aws_subnet_ids.nexus_vpc_subnets.ids}"]

access_logs {
  bucket = "${aws_s3_bucket.nexus-s3-bucket-logs.bucket}"
  prefix = "nexus-lb"
  enabled = true
 }
}

// Provides a target group to use with our ALB
resource "aws_alb_target_group" "nexus_alb_target_group" {
  name     = "${var.target_group_name}"
  port     = "${var.target_group_port}"
  protocol = "HTTP"
  vpc_id   = "${var.vpc_id}"
  tags {
    name = "${var.target_group_name}"
  }

  health_check {
    healthy_threshold   = 3
    unhealthy_threshold = 10
    timeout             = 5
    interval            = 10
    path                = "${var.target_group_path}"
    port                = "${var.target_group_port}"
  }
}


// Listens for traffic on a specific port
resource "aws_alb_listener" "nexus_alb_listener" {
  load_balancer_arn = "${aws_alb.nexus_alb.arn}"
  port              = "${var.alb_listener_port}"
  protocol          = "${var.alb_listener_protocol}"

  default_action {
    target_group_arn = "${aws_alb_target_group.nexus_alb_target_group.arn}"
    type             = "forward"
  }
}


// Provides the ALB listen rules
resource "aws_alb_listener_rule" "listener_rule" {
  depends_on   = ["aws_alb_target_group.nexus_alb_target_group"]
  listener_arn = "${aws_alb_listener.nexus_alb_listener.arn}"
  priority     = "${var.listener_rule_priority}"
  action {
    type             = "forward"
    target_group_arn = "${aws_alb_target_group.nexus_alb_target_group.id}"
  }
  condition {
    field  = "path-pattern"
    values = ["${var.nexus_alb_path}"]
  }
}

// Create a CNAME for the ALB
resource "aws_route53_record" "www" {
  zone_id = "${var.route_53_zone_id}"
  name    = "nexus-repo.${var.route_53_zone}"
  type    = "CNAME"
  ttl     = "300"
  records = ["${aws_alb.nexus_alb.dns_name}"]
}