Mark location as a required field for AlloyDB on-demand backup

.changelog/7688.txt

@@ -0,0 +1,3 @@
+```release-note:bug
+alloydb: changed `location` from `optional` to `required` for `google_alloydb_backup`. `location` had previously been marked as optional, but operations failed if it was omitted, and there was no way for `location` to be inherited from the provider configuration or from an environment variable. This means there was no way to have a working configuration without `location` specified.
+```

google-beta/resource_alloydb_backup.go

@@ -55,6 +55,12 @@ func ResourceAlloydbBackup() *schema.Resource {
 				DiffSuppressFunc: ProjectNumberDiffSuppress,
 				Description:      `The full resource name of the backup source cluster (e.g., projects/{project}/locations/{location}/clusters/{clusterId}).`,
 			},
+			"location": {
+				Type:        schema.TypeString,
+				Required:    true,
+				ForceNew:    true,
+				Description: `The location where the alloydb backup should reside.`,
+			},
 			"description": {
 				Type:        schema.TypeString,
 				Optional:    true,
@@ -67,12 +73,6 @@ func ResourceAlloydbBackup() *schema.Resource {
 				Description: `User-defined labels for the alloydb backup.`,
 				Elem:        &schema.Schema{Type: schema.TypeString},
 			},
-			"location": {
-				Type:        schema.TypeString,
-				Optional:    true,
-				ForceNew:    true,
-				Description: `The location where the alloydb backup should reside.`,
-			},
 			"create_time": {
 				Type:        schema.TypeString,
 				Computed:    true,

google-beta/resource_alloydb_backup_test.go

@@ -1,6 +1,7 @@
 package google
 
 import (
+	"regexp"
 	"testing"
 
 	"github.com/hashicorp/terraform-plugin-sdk/v2/helper/resource"
@@ -90,3 +91,69 @@ data "google_compute_network" "default" {
 }
 `, context)
 }
+
+// We expect an error when creating an on-demand backup without location.
+// Location is a `required` field.
+func TestAccAlloydbBackup_missingLocation(t *testing.T) {
+	t.Parallel()
+
+	context := map[string]interface{}{
+		"random_suffix": RandString(t, 10),
+	}
+
+	VcrTest(t, resource.TestCase{
+		PreCheck:                 func() { AccTestPreCheck(t) },
+		ProtoV5ProviderFactories: ProtoV5ProviderFactories(t),
+		CheckDestroy:             testAccCheckAlloydbBackupDestroyProducer(t),
+		Steps: []resource.TestStep{
+			{
+				Config:      testAccAlloydbBackup_missingLocation(context),
+				ExpectError: regexp.MustCompile("Missing required argument"),
+			},
+		},
+	})
+}
+
+func testAccAlloydbBackup_missingLocation(context map[string]interface{}) string {
+	return Nprintf(`
+resource "google_alloydb_backup" "default" {
+  backup_id    = "tf-test-alloydb-backup%{random_suffix}"
+  cluster_name = google_alloydb_cluster.default.name
+  depends_on = [google_alloydb_instance.default]
+}
+
+resource "google_alloydb_cluster" "default" {
+  location = "us-central1"
+  cluster_id = "tf-test-alloydb-cluster%{random_suffix}"
+  network    = "projects/${data.google_project.project.number}/global/networks/${google_compute_network.default.name}"
+}
+
+data "google_project" "project" { }
+
+resource "google_compute_network" "default" {
+  name = "tf-test-alloydb-cluster%{random_suffix}"
+}
+
+resource "google_alloydb_instance" "default" {
+  cluster       = google_alloydb_cluster.default.name
+  instance_id   = "tf-test-alloydb-instance%{random_suffix}"
+  instance_type = "PRIMARY"
+
+  depends_on = [google_service_networking_connection.vpc_connection]
+}
+
+resource "google_compute_global_address" "private_ip_alloc" {
+  name          =  "tf-test-alloydb-cluster%{random_suffix}"
+  address_type  = "INTERNAL"
+  purpose       = "VPC_PEERING"
+  prefix_length = 16
+  network       = "projects/${data.google_project.project.number}/global/networks/${google_compute_network.default.name}"
+}
+
+resource "google_service_networking_connection" "vpc_connection" {
+  network                 = "projects/${data.google_project.project.number}/global/networks/${google_compute_network.default.name}"
+  service                 = "servicenetworking.googleapis.com"
+  reserved_peering_ranges = [google_compute_global_address.private_ip_alloc.name]
+}
+`, context)
+}

website/docs/r/alloydb_backup.html.markdown

@@ -144,6 +144,10 @@ The following arguments are supported:
   (Required)
   The ID of the alloydb backup.
 
+* `location` -
+  (Required)
+  The location where the alloydb backup should reside.
+
 
 - - -
 
@@ -156,10 +160,6 @@ The following arguments are supported:
   (Optional)
   User-provided description of the backup.
 
-* `location` -
-  (Optional)
-  The location where the alloydb backup should reside.
-
 * `project` - (Optional) The ID of the project in which the resource belongs.
     If it is not provided, the provider project is used.