data/azure: re-organize vnet to create explicit deps to internal dns …

…zone before any resource in vnet

Previous commit [1] created explicit deps to make sure VMs were not created before internal DNS zone and VNET attachement.
There is still cases where LBs etc like resources in VNET block the internal DNS zone creation because of azure issues [2]

[1]: 08c8bc5
[2]: MicrosoftDocs/azure-docs#13728

data/data/azure/main.tf

@@ -39,6 +39,7 @@ module "bootstrap" {
 
 module "vnet" {
   source              = "./vnet"
+  vnet_name           = azurerm_virtual_network.cluster_vnet.name
   resource_group_name = azurerm_resource_group.main.name
   vnet_cidr           = var.machine_cidr
   master_subnet_cidr  = local.master_subnet_cidr
@@ -47,6 +48,9 @@ module "vnet" {
   region              = var.azure_region
   dns_label           = var.cluster_id
   master_count        = var.master_count
+
+  # This is to create explicit dependency on private zone to exist before VMs are created in the vnet. https://github.com/MicrosoftDocs/azure-docs/issues/13728
+  private_dns_zone_id = azurerm_dns_zone.private.id
 }
 
 module "master" {
@@ -123,5 +127,12 @@ resource "azurerm_dns_zone" "private" {
   name                           = var.cluster_domain
   resource_group_name            = azurerm_resource_group.main.name
   zone_type                      = "Private"
-  resolution_virtual_network_ids = [module.vnet.vnet_id]
+  resolution_virtual_network_ids = [azurerm_virtual_network.cluster_vnet.id]
+}
+
+resource "azurerm_virtual_network" "cluster_vnet" {
+  name                = "${var.cluster_id}-vnet"
+  resource_group_name = azurerm_resource_group.main.name
+  location            = var.azure_region
+  address_space       = [var.machine_cidr]
 }

data/data/azure/vnet/common.tf

@@ -3,8 +3,6 @@
 
 // Only reference data sources which are guaranteed to exist at any time (above) in this locals{} block
 locals {
-  vnet_id = azurerm_virtual_network.cluster_vnet.id
-
   subnet_ids = azurerm_subnet.master_subnet.id
 
   lb_fqdn = azurerm_lb.public.id

data/data/azure/vnet/outputs.tf

@@ -1,7 +1,3 @@
-output "vnet_id" {
-  value = local.vnet_id
-}
-
 output "cluster-pip" {
   value = azurerm_public_ip.cluster_public_ip.ip_address
 }

data/data/azure/vnet/variables.tf

@@ -1,3 +1,7 @@
+variable "vnet_name" {
+  type = string
+}
+
 variable "vnet_cidr" {
   type = string
 }
@@ -53,3 +57,7 @@ variable "master_count" {
   default     = "3"
 }
 
+variable "private_dns_zone_id" {
+  type        = string
+  description = "This is to create explicit dependency on private zone to exist before VMs are created in the vnet. https://github.com/MicrosoftDocs/azure-docs/issues/13728"
+}

data/data/azure/vnet/vnet.tf

@@ -1,10 +1,3 @@
-resource "azurerm_virtual_network" "cluster_vnet" {
-  name                = "${var.cluster_id}-vnet"
-  resource_group_name = var.resource_group_name
-  location            = var.region
-  address_space       = [var.vnet_cidr]
-}
-
 resource "azurerm_route_table" "route_table" {
   name                = "${var.cluster_id}-node-routetable"
   location            = var.region
@@ -14,14 +7,14 @@ resource "azurerm_route_table" "route_table" {
 resource "azurerm_subnet" "master_subnet" {
   resource_group_name  = var.resource_group_name
   address_prefix       = var.master_subnet_cidr
-  virtual_network_name = azurerm_virtual_network.cluster_vnet.name
+  virtual_network_name = var.vnet_name
   name                 = "${var.cluster_id}-controlplane-subnet"
 }
 
 resource "azurerm_subnet" "node_subnet" {
   resource_group_name  = var.resource_group_name
   address_prefix       = var.node_subnet_cidr
-  virtual_network_name = azurerm_virtual_network.cluster_vnet.name
+  virtual_network_name = var.vnet_name
   name                 = "${var.cluster_id}-node-subnet"
 }