ELB config in modules\aws-demo-environment\main.tf

resource "aws_iam_server_certificate" "elb_cert" {
  name_prefix       = "letfdemo-cert-"
  certificate_body  = "${var.demo_env_cert_body}"
  certificate_chain = "${var.demo_env_cert_chain}"
  private_key       = "${var.demo_env_cert_privkey}"

  lifecycle {
    create_before_destroy = true
  }
}

resource "aws_elb" "web" {
  name = "letfdemo-elb-www"
  
  subnets         = ["${aws_subnet.public.id}"]
  security_groups = ["${aws_security_group.elb.id}"]
  instances       = ["${aws_instance.nginx.*.id}"]

  listener {
    instance_port      = 80
    instance_protocol  = "http"
    lb_port            = 443
    lb_protocol        = "https"
    ssl_certificate_id = "${aws_iam_server_certificate.elb_cert.arn}"

  }
}