fix: change asm module depends_on method (terraform-google-modules#1354)

Author: apeabody

modules/asm/README.md

@@ -60,7 +60,7 @@ To deploy this config:
 | enable\_vpc\_sc | Determines whether to enable VPC-SC for this ASM installation. For more information read https://cloud.google.com/service-mesh/docs/managed/vpc-sc | `bool` | `false` | no |
 | fleet\_id | The fleet to use for this ASM installation. | `string` | `""` | no |
 | internal\_ip | Use internal ip for the cluster endpoint when running kubectl commands. | `bool` | `false` | no |
-| module\_depends\_on | List of modules or resources this module depends on. | `list(any)` | `[]` | no |
+| module\_depends\_on | List of modules or resources this module depends on.  If multiple, all items must be the same type. | `list(any)` | `[]` | no |
 | multicluster\_mode | [Preview] Determines whether remote secrets should be autogenerated across fleet cluster. | `string` | `"manual"` | no |
 | project\_id | The project in which the resource belongs. | `string` | n/a | yes |
 

modules/asm/main.tf

@@ -48,7 +48,7 @@ resource "kubernetes_config_map" "asm_options" {
     ASM_OPTS          = var.enable_cni ? "CNI=on" : null
   }
 
-  depends_on = [google_gke_hub_membership.membership, google_gke_hub_feature.mesh]
+  depends_on = [google_gke_hub_membership.membership, google_gke_hub_feature.mesh, var.module_depends_on]
 }
 
 module "cpr" {
@@ -63,5 +63,5 @@ module "cpr" {
   kubectl_create_command  = "${path.module}/scripts/create_cpr.sh ${local.revision_name} ${local.channel} ${var.enable_cni} ${var.enable_vpc_sc}"
   kubectl_destroy_command = "${path.module}/scripts/destroy_cpr.sh ${local.revision_name}"
 
-  module_depends_on = concat([kubernetes_config_map.asm_options], var.module_depends_on)
+  module_depends_on = [kubernetes_config_map.asm_options]
 }

modules/asm/variables.tf

@@ -94,7 +94,7 @@ variable "internal_ip" {
 }
 
 variable "module_depends_on" {
-  description = "List of modules or resources this module depends on."
+  description = "List of modules or resources this module depends on.  If multiple, all items must be the same type."
   type        = list(any)
   default     = []
 }