kubespray/contrib/terraform/aws/modules/elb/main.tf

resource "aws_security_group" "aws-elb" {
  name   = "kubernetes-${var.aws_cluster_name}-securitygroup-elb"
  vpc_id = var.aws_vpc_id

  tags = merge(var.default_tags, map(
    "Name", "kubernetes-${var.aws_cluster_name}-securitygroup-elb"
  ))
}

resource "aws_security_group_rule" "aws-allow-api-access" {
  type              = "ingress"
  from_port         = var.aws_elb_api_port
  to_port           = var.k8s_secure_api_port
  protocol          = "TCP"
  cidr_blocks       = ["0.0.0.0/0"]
  security_group_id = aws_security_group.aws-elb.id
}

resource "aws_security_group_rule" "aws-allow-api-egress" {
  type              = "egress"
  from_port         = 0
  to_port           = 65535
  protocol          = "TCP"
  cidr_blocks       = ["0.0.0.0/0"]
  security_group_id = aws_security_group.aws-elb.id
}

# Create a new AWS ELB for K8S API
resource "aws_elb" "aws-elb-api" {
  name            = "kubernetes-elb-${var.aws_cluster_name}"
  subnets         = var.aws_subnet_ids_public
  security_groups = [aws_security_group.aws-elb.id]

  listener {
    instance_port     = var.k8s_secure_api_port
    instance_protocol = "tcp"
    lb_port           = var.aws_elb_api_port
    lb_protocol       = "tcp"
  }

  health_check {
    healthy_threshold   = 2
    unhealthy_threshold = 2
    timeout             = 3
    target              = "HTTPS:${var.k8s_secure_api_port}/healthz"
    interval            = 30
  }

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

  tags = merge(var.default_tags, map(
    "Name", "kubernetes-${var.aws_cluster_name}-elb-api"
  ))
}