Modular Global HTTP Load Balancer for GCE using forwarding rules.

module "gce-lb-http" {
  source            = "GoogleCloudPlatform/lb-http/google"
  name              = "group-http-lb"
  target_tags       = ["${module.mig1.target_tags}", "${module.mig2.target_tags}"]
  backends          = {
    "0" = [
      { group = "${module.mig1.instance_group}" },
      { group = "${module.mig2.instance_group}" }
    ],
  }
  backend_params    = [
    # health check path, port name, port number, timeout seconds.
    "/,http,80,10"
  ]
}

• google_compute_global_forwarding_rule.http: The global HTTP forwarding rule.
• google_compute_global_forwarding_rule.https: The global HTTPS forwarding rule created when ssl is true.
• google_compute_target_http_proxy.default: The HTTP proxy resource that binds the url map. Created when input ssl is false.
• google_compute_target_https_proxy.default: The HTTPS proxy resource that binds the url map. Created when input ssl is true.
• google_compute_ssl_certificate.default: The certificate resource created when input ssl is true.
• google_compute_url_map.default: The default URL map resource when input url_map is not provided.
• google_compute_backend_service.default.*: The backend services created for each of the backend_params elements.
• google_compute_http_health_check.default.*: Health check resources create for each of the backend services.
• google_compute_firewall.default-hc: Firewall rule created for each of the backed services to alllow health checks to the instance group.