feat: add a static inbound option for the private dns resolver

infrastructure/modules/private-dns-zone-resolver/main.tf

@@ -18,6 +18,7 @@ resource "azurerm_private_dns_resolver_inbound_endpoint" "private_dns_resolver_i
 
   ip_configurations {
     private_ip_allocation_method = var.inbound_endpoint_config.private_ip_allocation_method
+    private_ip_address           = var.inbound_endpoint_config.private_ip_allocation_method == "Static" ? var.inbound_endpoint_config.private_ip_address : null
     subnet_id                    = var.inbound_endpoint_config.subnet_id
   }
 }

infrastructure/modules/private-dns-zone-resolver/tfdocs.md

@@ -34,7 +34,7 @@ The following input variables are optional (have default values):
 
 ### <a name="input_inbound_endpoint_config"></a> [inbound\_endpoint\_config](#input\_inbound\_endpoint\_config)
 
-Description: The configuration for the inbound endpoint.
+Description: The configuration for the inbound endpoint. `private_ip_allocation_method` must be either `"Static"` or `"Dynamic"`. `private_ip_address` is optional but **required** when `private_ip_allocation_method` is set to `"Static"`.
 
 Type:
 
@@ -43,6 +43,7 @@ object({
     name                         = string
     private_ip_allocation_method = string
     subnet_id                    = string
+    private_ip_address           = optional(string, null)
   })
 ```
 
@@ -51,8 +52,9 @@ Default:
 ```json
 {
   "name": "",
-  "private_ip_allocation_method": "",
-  "subnet_id": ""
+  "private_ip_allocation_method": "Dynamic",
+  "subnet_id": "",
+  "private_ip_address": null
 }
 ```
 

infrastructure/modules/private-dns-zone-resolver/variables.tf

@@ -23,11 +23,23 @@ variable "inbound_endpoint_config" {
     name                         = string
     private_ip_allocation_method = string
     subnet_id                    = string
+    private_ip_address           = optional(string, null)
   })
   default = {
     name                         = ""
-    private_ip_allocation_method = ""
+    private_ip_allocation_method = "Dynamic"
     subnet_id                    = ""
+    private_ip_address           = null
+  }
+
+  validation {
+    condition     = contains(["Static", "Dynamic"], var.inbound_endpoint_config.private_ip_allocation_method)
+    error_message = "inbound_endpoint_config.private_ip_allocation_method must be either 'Static' or 'Dynamic'."
+  }
+
+  validation {
+    condition     = !(var.inbound_endpoint_config.private_ip_allocation_method == "Static" && var.inbound_endpoint_config.private_ip_address == null)
+    error_message = "inbound_endpoint_config.private_ip_address must be provided when private_ip_allocation_method is set to 'Static'."
   }
 }