cannot create internal load balancer on a subnetwork

[justinabrahms]

TL;DR

the module doesn't take a subnetwork parameter, which is required to create an ip address within the right subnetwork range.

Expected behavior

I should be able to pass in my subnetwork.

Observed behavior

╷
│ Error: Error creating GlobalForwardingRule: googleapi: Error 400: Invalid value for field 'resource.IPAddress': '192.168.87.235'. Address '192.168.87.235' is not in the subnetwork ranges of network 'default'., invalid
│ 
│   with module.gce-internal-lb-http.google_compute_global_forwarding_rule.http[0],
│   on .terraform/modules/gce-internal-lb-http/main.tf line 32, in resource "google_compute_global_forwarding_rule" "http":
│   32: resource "google_compute_global_forwarding_rule" "http" {
│ 
╵

Terraform Configuration

resource "google_compute_address" "internal-cluster" {
  name  = "${var.environment}-internal-ip"
  address_type = "INTERNAL"
  subnetwork   = google_compute_subnetwork.cluster.id
}

module "gce-internal-lb-http" {
  source = "GoogleCloudPlatform/lb-http/google"
  version = "~> 9.0"

  project = local.project_id
  name = "${var.environment}-internal-http-lb"
  load_balancing_scheme = "INTERNAL_MANAGED"
  target_tags = ["client"]
  create_address = false
  address = google_compute_address.internal-cluster.address

  network =   module.networking.network_name


  backends = {
    default = {
      port_name = "traefik"
      protocol = "HTTP"
      timeout_sec = 10
      enable_cdn = false

      health_check = {
        request_path = "/___heartbeat___"
        port_name = "traefik"
        port = 80 # required so that the firewall knows which port to allow
        protocol = "HTTP"
      }

      log_config = {
        enable = false
      }

      groups = [
#        {group = my-group-here}
      ]

      iap_config = {
        enable = false
      }
    }
  }
}

Terraform Version

Terraform v1.5.7
on linux_amd64
+ provider registry.terraform.io/cloudflare/cloudflare v4.9.0
+ provider registry.terraform.io/hashicorp/google v4.72.0
+ provider registry.terraform.io/hashicorp/google-beta v4.84.0
+ provider registry.terraform.io/hashicorp/nomad v1.4.20
+ provider registry.terraform.io/hashicorp/null v3.2.1
+ provider registry.terraform.io/hashicorp/random v3.5.1
+ provider registry.terraform.io/integrations/github v5.29.0
+ provider registry.terraform.io/tailscale/tailscale v0.13.7

Your version of Terraform is out of date! The latest version
is 1.6.0. You can update by downloading from https://www.terraform.io/downloads.ht

Additional information

No response

[justinabrahms]

Playing around with making a PR and this is more complex than it sounded. I'm not seeing how to make global forwarding rules that point to internal ips that are owned by a subnetwork. Just passing along the subnetwork yields this error, which I believe means not using global forwarding rules:

│ Error: Error creating GlobalForwardingRule: googleapi: Error 400: Invalid value for field 'resource.subnetwork': 'projects/<mine>/regions/us-central1/subnetworks/<subnet>'. The network/subnetwork field(s) can only be used for INTERNAL forwarding rules., invalid
│ 
│   with module.gce-internal-lb-http.google_compute_global_forwarding_rule.http[0],
│   on ../modules/terraform-google-lb-http/main.tf line 33, in resource "google_compute_global_forwarding_rule" "http":
│   33: resource "google_compute_global_forwarding_rule" "http" {

[imrannayer]

@justinabrahms this module can only create External Application load balancers of type:

1. Classic
2. Envoy based
3. Traffic director