Set instance zone in net vpc route to avoid recreation (#90)

modules/net-vpc/README.md

@@ -112,20 +112,21 @@ module "vpc-host" {
 | name | The name of the network being created | <code title="">string</code> | ✓ |  |
 | project_id | The ID of the project where this VPC will be created | <code title="">string</code> | ✓ |  |
 | *auto_create_subnetworks* | Set to true to create an auto mode subnet, defaults to custom mode. | <code title="">bool</code> |  | <code title="">false</code> |
+| *delete_default_routes_on_create* | Set to true to delete the default routes at creation time. | <code title="">bool</code> |  | <code title="">false</code> |
 | *description* | An optional description of this resource (triggers recreation on change). | <code title="">string</code> |  | <code title="">Terraform-managed.</code> |
-| *iam_members* | List of IAM members keyed by subnet 'region/name' and role. | <code title="map&#40;map&#40;list&#40;string&#41;&#41;&#41;">map(map(list(string)))</code> |  | <code title="">null</code> |
-| *iam_roles* | List of IAM roles keyed by subnet 'region/name'. | <code title="map&#40;list&#40;string&#41;&#41;">map(list(string))</code> |  | <code title="">null</code> |
+| *iam_members* | List of IAM members keyed by subnet 'region/name' and role. | <code title="map&#40;map&#40;list&#40;string&#41;&#41;&#41;">map(map(list(string)))</code> |  | <code title="">{}</code> |
+| *iam_roles* | List of IAM roles keyed by subnet 'region/name'. | <code title="map&#40;list&#40;string&#41;&#41;">map(list(string))</code> |  | <code title="">{}</code> |
 | *log_config_defaults* | Default configuration for flow logs when enabled. | <code title="object&#40;&#123;&#10;aggregation_interval &#61; string&#10;flow_sampling        &#61; number&#10;metadata             &#61; string&#10;&#125;&#41;">object({...})</code> |  | <code title="&#123;&#10;aggregation_interval &#61; &#34;INTERVAL_5_SEC&#34;&#10;flow_sampling        &#61; 0.5&#10;metadata             &#61; &#34;INCLUDE_ALL_METADATA&#34;&#10;&#125;">...</code> |
-| *log_configs* | Map keyed by subnet 'region/name' of optional configurations for flow logs when enabled. | <code title="map&#40;map&#40;string&#41;&#41;">map(map(string))</code> |  | <code title="">null</code> |
+| *log_configs* | Map keyed by subnet 'region/name' of optional configurations for flow logs when enabled. | <code title="map&#40;map&#40;string&#41;&#41;">map(map(string))</code> |  | <code title="">{}</code> |
 | *peering_config* | VPC peering configuration. | <code title="object&#40;&#123;&#10;peer_vpc_self_link &#61; string&#10;export_routes      &#61; bool&#10;import_routes      &#61; bool&#10;&#125;&#41;">object({...})</code> |  | <code title="">null</code> |
-| *routes* | Network routes, keyed by name. | <code title="map&#40;object&#40;&#123;&#10;dest_range    &#61; string&#10;priority      &#61; number&#10;tags          &#61; list&#40;string&#41;&#10;next_hop_type &#61; string &#35; gateway, instance, ip, vpn_tunnel, ilb&#10;next_hop      &#61; string&#10;&#125;&#41;&#41;">map(object({...}))</code> |  | <code title="">null</code> |
+| *routes* | Network routes, keyed by name. | <code title="map&#40;object&#40;&#123;&#10;dest_range    &#61; string&#10;priority      &#61; number&#10;tags          &#61; list&#40;string&#41;&#10;next_hop_type &#61; string &#35; gateway, instance, ip, vpn_tunnel, ilb&#10;next_hop      &#61; string&#10;&#125;&#41;&#41;">map(object({...}))</code> |  | <code title="">{}</code> |
 | *routing_mode* | The network routing mode (default 'GLOBAL') | <code title="">string</code> |  | <code title="">GLOBAL</code> |
 | *shared_vpc_host* | Enable shared VPC for this project. | <code title="">bool</code> |  | <code title="">false</code> |
 | *shared_vpc_service_projects* | Shared VPC service projects to register with this host | <code title="list&#40;string&#41;">list(string)</code> |  | <code title="">[]</code> |
 | *subnet_descriptions* | Optional map of subnet descriptions, keyed by subnet 'region/name'. | <code title="map&#40;string&#41;">map(string)</code> |  | <code title="">{}</code> |
 | *subnet_flow_logs* | Optional map of boolean to control flow logs (default is disabled), keyed by subnet 'region/name'. | <code title="map&#40;bool&#41;">map(bool)</code> |  | <code title="">{}</code> |
 | *subnet_private_access* | Optional map of boolean to control private Google access (default is enabled), keyed by subnet 'region/name'. | <code title="map&#40;bool&#41;">map(bool)</code> |  | <code title="">{}</code> |
-| *subnets* | The list of subnets being created | <code title="map&#40;object&#40;&#123;&#10;ip_cidr_range      &#61; string&#10;region             &#61; string&#10;secondary_ip_range &#61; map&#40;string&#41;&#10;&#125;&#41;&#41;">map(object({...}))</code> |  | <code title="">null</code> |
+| *subnets* | The list of subnets being created | <code title="list&#40;object&#40;&#123;&#10;name               &#61; string&#10;ip_cidr_range      &#61; string&#10;name               &#61; string&#10;region             &#61; string&#10;secondary_ip_range &#61; map&#40;string&#41;&#10;&#125;&#41;&#41;">list(object({...}))</code> |  | <code title="">[]</code> |
 
 ## Outputs
 
@@ -136,10 +137,10 @@ module "vpc-host" {
 | network | Network resource. |  |
 | project_id | Shared VPC host project id. |  |
 | self_link | The URI of the VPC being created. |  |
-| subnet_ips | Map of subnet address ranges keyed by 'region/name'. |  |
-| subnet_regions | Map of subnet regions keyed by 'region/name'. |  |
-| subnet_secondary_ranges | Map of subnet secondary ranges keyed by 'region/name'. |  |
-| subnet_self_links | Map of subnet self links keyed by 'region/name'. |  |
+| subnet_ips | Map of subnet address ranges keyed by name. |  |
+| subnet_regions | Map of subnet regions keyed by name. |  |
+| subnet_secondary_ranges | Map of subnet secondary ranges keyed by name. |  |
+| subnet_self_links | Map of subnet self links keyed by name. |  |
 | subnets | Subnet resources. |  |
 <!-- END TFDOC -->
 

modules/net-vpc/main.tf

@@ -64,7 +64,7 @@ locals {
   }
   subnets = {
     for subnet in var.subnets :
-      "${subnet.region}/${subnet.name}" => subnet
+    "${subnet.region}/${subnet.name}" => subnet
   }
 }
 
@@ -184,6 +184,8 @@ resource "google_compute_route" "instance" {
   priority          = each.value.priority
   tags              = each.value.tags
   next_hop_instance = each.value.next_hop
+  # not setting the instance zone will trigger a refresh
+  next_hop_instance_zone = regex("zones/([^/]+)/", each.value.next_hop)[0]
 }
 
 resource "google_compute_route" "ip" {

modules/net-vpc/variables.tf

@@ -35,19 +35,19 @@ variable "description" {
 variable "iam_roles" {
   description = "List of IAM roles keyed by subnet 'region/name'."
   type        = map(list(string))
-  default     = null
+  default     = {}
 }
 
 variable "iam_members" {
   description = "List of IAM members keyed by subnet 'region/name' and role."
   type        = map(map(list(string)))
-  default     = null
+  default     = {}
 }
 
 variable "log_configs" {
   description = "Map keyed by subnet 'region/name' of optional configurations for flow logs when enabled."
   type        = map(map(string))
-  default     = null
+  default     = {}
 }
 
 variable "log_config_defaults" {
@@ -93,7 +93,7 @@ variable "routes" {
     next_hop_type = string # gateway, instance, ip, vpn_tunnel, ilb
     next_hop      = string
   }))
-  default = null
+  default = {}
 }
 
 variable "routing_mode" {