umig access_config values only apply to a single instance

[rebelpacket]

TL;DR

I'm trying to build out a umig of 3 compute instances, with external IP addresses to accept load balanced traffic.
When I specify null values for the access_config parameters, only the first compute instance gets an external IP address.

Expected behavior

Both instances get external ip addresses

Observed behavior

Only the first instance gets an external IP address

Terraform Configuration

locals {
  rma_named_ports = [{
    name = var.rma_service_port_name
    port = var.rma_service_port
  }]
  access_config = [{
    nat_ip       = null
    network_tier = null
  }]
}

module "rma-web-central1-template" {
  source        = "terraform-google-modules/vm/google//modules/instance_template"
  source_image  = var.rma_source_image
  machine_type  = "n1-standard-4"
  region        = var.region
  project_id    = var.project_id
  access_config = local.access_config
  subnetwork    = "production-us-central1-vpc"
  tags          = ["ssh", "webserver", "rma"]
  disk_size_gb  = "20"
  metadata = {
    env   = "production"
    owner = "engineering"
    role  = "webserver"
  }
  service_account = var.rma_service_account
}

module "rma-webservers-central1" {
  source            = "terraform-google-modules/vm/google//modules/umig"
  version           = "7.4.0"
  project_id        = var.project_id
  subnetwork        = "production-us-central1-vpc"
  num_instances     = var.rma_num_webservers
  hostname          = "rma-web-central1"
  instance_template = module.rma-web-central1-template.self_link
  named_ports       = local.rma_named_ports
  region            = var.region
  access_config     = [local.access_config]
}

Terraform Version

Terraform v1.0.10
on darwin_amd64

Additional information

Below is the change when I updated the access_config local variable. It appears that the count.index on line 61 in main.tf is likely the cause of this issue.

Terraform will perform the following actions:

  # module.rma-webservers-central1.google_compute_instance_from_template.compute_instance[0] will be updated in-place
  ~ resource "google_compute_instance_from_template" "compute_instance" {
        id                       = "projects/xxxxx/zones/us-central1-a/instances/rma-web-central1-001"
        name                     = "rma-web-central1-001"
        tags                     = [
            "rma",
            "ssh",
            "webserver",
        ]
        # (21 unchanged attributes hidden)



      ~ network_interface {
          ~ access_config      = [
              + {
                  + nat_ip                 = null
                  + network_tier           = null
                  + public_ptr_domain_name = null
                },
            ]
            name               = "nic0"
            # (6 unchanged attributes hidden)
        }


        # (4 unchanged blocks hidden)
    }

Plan: 0 to add, 1 to change, 0 to destroy.

[github-actions]

This issue is stale because it has been open 60 days with no activity. Remove stale label or comment or this will be closed in 7 days