azurerm_subnet - add delete_on_destroy to optionally skip Azure resource deletion on destroy

Author: aleqsss

internal/services/network/subnet_resource.go

@@ -276,6 +276,12 @@ func resourceSubnet() *pluginsdk.Resource {
 				Optional: true,
 			},
 
+			"delete_on_destroy": {
+				Type:     pluginsdk.TypeBool,
+				Optional: true,
+				Default:  true,
+			},
+
 			"private_endpoint_network_policies": {
 				Type:         pluginsdk.TypeString,
 				Optional:     true,
@@ -639,6 +645,11 @@ func resourceSubnetDelete(d *pluginsdk.ResourceData, meta interface{}) error {
 	locks.ByName(id.SubnetName, SubnetResourceName)
 	defer locks.UnlockByName(id.SubnetName, SubnetResourceName)
 
+	if !d.Get("delete_on_destroy").(bool) {
+		log.Printf("[DEBUG] Skipping deletion for %s because `delete_on_destroy` is false", *id)
+		return nil
+	}
+
 	if err := client.DeleteThenPoll(ctx, *id); err != nil {
 		return fmt.Errorf("deleting %s: %+v", *id, err)
 	}

internal/services/network/subnet_resource_test.go

@@ -149,6 +149,30 @@ func TestAccSubnet_defaultOutbound(t *testing.T) {
 	})
 }
 
+func TestAccSubnet_deleteOnDestroy(t *testing.T) {
+	data := acceptance.BuildTestData(t, "azurerm_subnet", "internal")
+	r := SubnetResource{}
+
+	data.ResourceTest(t, r, []acceptance.TestStep{
+		{
+			Config: r.deleteOnDestroy(data, false),
+			Check: acceptance.ComposeTestCheckFunc(
+				check.That(data.ResourceName).ExistsInAzure(r),
+				check.That(data.ResourceName).Key("delete_on_destroy").HasValue("false"),
+			),
+		},
+		data.ImportStep("delete_on_destroy"),
+		{
+			Config: r.deleteOnDestroy(data, true),
+			Check: acceptance.ComposeTestCheckFunc(
+				check.That(data.ResourceName).ExistsInAzure(r),
+				check.That(data.ResourceName).Key("delete_on_destroy").HasValue("true"),
+			),
+		},
+		data.ImportStep("delete_on_destroy"),
+	})
+}
+
 func TestAccSubnet_delegation(t *testing.T) {
 	data := acceptance.BuildTestData(t, "azurerm_subnet", "test")
 	r := SubnetResource{}
@@ -705,6 +729,19 @@ resource "azurerm_subnet" "internal" {
 `, r.template(data), enabled)
 }
 
+func (r SubnetResource) deleteOnDestroy(data acceptance.TestData, deleteOnDestroy bool) string {
+	return fmt.Sprintf(`
+%s
+resource "azurerm_subnet" "internal" {
+	name                 = "internal"
+	resource_group_name  = azurerm_resource_group.test.name
+	virtual_network_name = azurerm_virtual_network.test.name
+	address_prefixes     = ["10.0.2.0/24"]
+	delete_on_destroy    = %t
+}
+`, r.template(data), deleteOnDestroy)
+}
+
 func (r SubnetResource) delegationUpdated(data acceptance.TestData) string {
 	return fmt.Sprintf(`
 %s

website/docs/r/subnet.html.markdown

@@ -65,6 +65,8 @@ The following arguments are supported:
 
 * `delegation` - (Optional) One or more `delegation` blocks as defined below.
 
+* `delete_on_destroy` - (Optional) Should the Subnet be deleted in Azure when this resource is destroyed? Defaults to `true`. When set to `false`, Terraform will remove this resource from state without deleting the Subnet in Azure.
+
 * `default_outbound_access_enabled` - (Optional) Enable default outbound access to the internet for the subnet. Defaults to `true`.
 
 * `ip_address_pool` - (Optional) An `ip_address_pool` block as defined below.