Add restoreBackup support for sql db instance

.changelog/4336.txt

@@ -0,0 +1,3 @@
+```release-note:enhancement
+sql: added restore from backup support to `google_sql_database_instance`
+```

google/resource_sql_database_instance.go

@@ -572,6 +572,30 @@ settings.backup_configuration.binary_log_enabled are both set to true.`,
 				Computed:    true,
 				Description: `The URI of the created resource.`,
 			},
+			"restore_backup_context": {
+				Type:     schema.TypeList,
+				Optional: true,
+				MaxItems: 1,
+				Elem: &schema.Resource{
+					Schema: map[string]*schema.Schema{
+						"backup_run_id": {
+							Type:        schema.TypeInt,
+							Required:    true,
+							Description: `The ID of the backup run to restore from.`,
+						},
+						"instance_id": {
+							Type:        schema.TypeString,
+							Optional:    true,
+							Description: `The ID of the instance that the backup was taken from.`,
+						},
+						"project": {
+							Type:        schema.TypeString,
+							Optional:    true,
+							Description: `The full project ID of the source instance.`,
+						},
+					},
+				},
+			},
 		},
 		UseJSONNumber: true,
 	}
@@ -739,6 +763,14 @@ func resourceSqlDatabaseInstanceCreate(d *schema.ResourceData, meta interface{})
 		}
 	}
 
+	// Perform a backup restore if the backup context exists
+	if r, ok := d.GetOk("restore_backup_context"); ok {
+		err = sqlDatabaseInstanceRestoreFromBackup(d, config, userAgent, project, name, r)
+		if err != nil {
+			return err
+		}
+	}
+
 	return nil
 }
 
@@ -1027,6 +1059,16 @@ func resourceSqlDatabaseInstanceUpdate(d *schema.ResourceData, meta interface{})
 		return err
 	}
 
+	// Perform a backup restore if the backup context exists and has changed
+	if r, ok := d.GetOk("restore_backup_context"); ok {
+		if d.HasChange("restore_backup_context") {
+			err = sqlDatabaseInstanceRestoreFromBackup(d, config, userAgent, project, d.Get("name").(string), r)
+			if err != nil {
+				return err
+			}
+		}
+	}
+
 	return resourceSqlDatabaseInstanceRead(d, meta)
 }
 
@@ -1319,3 +1361,41 @@ func sqlDatabaseInstanceServiceNetworkPrecheck(d *schema.ResourceData, config *C
 
 	return nil
 }
+
+func expandRestoreBackupContext(configured []interface{}) *sqladmin.RestoreBackupContext {
+	if len(configured) == 0 || configured[0] == nil {
+		return nil
+	}
+
+	_rc := configured[0].(map[string]interface{})
+	return &sqladmin.RestoreBackupContext{
+		BackupRunId: int64(_rc["backup_run_id"].(int)),
+		InstanceId:  _rc["instance_id"].(string),
+		Project:     _rc["project"].(string),
+	}
+}
+
+func sqlDatabaseInstanceRestoreFromBackup(d *schema.ResourceData, config *Config, userAgent, project, instanceId string, r interface{}) error {
+	log.Printf("[DEBUG] Initiating SQL database instance backup restore")
+	restoreContext := r.([]interface{})
+
+	backupRequest := &sqladmin.InstancesRestoreBackupRequest{
+		RestoreBackupContext: expandRestoreBackupContext(restoreContext),
+	}
+
+	var op *sqladmin.Operation
+	err := retryTimeDuration(func() (operr error) {
+		op, operr = config.NewSqlAdminClient(userAgent).Instances.RestoreBackup(project, instanceId, backupRequest).Do()
+		return operr
+	}, d.Timeout(schema.TimeoutUpdate), isSqlOperationInProgressError)
+	if err != nil {
+		return fmt.Errorf("Error, failed to restore instance from backup %s: %s", instanceId, err)
+	}
+
+	err = sqlAdminOperationWaitTime(config, op, project, "Restore Backup", userAgent, d.Timeout(schema.TimeoutUpdate))
+	if err != nil {
+		return err
+	}
+
+	return nil
+}

google/resource_sql_database_instance_test.go

@@ -665,6 +665,71 @@ func TestAccSqlDatabaseInstance_basic_with_user_labels(t *testing.T) {
 	})
 }
 
+func TestAccSqlDatabaseInstance_createFromBackup(t *testing.T) {
+	// Sqladmin client
+	skipIfVcr(t)
+	t.Parallel()
+
+	context := map[string]interface{}{
+		"random_suffix":    randString(t, 10),
+		"original_db_name": BootstrapSharedSQLInstanceBackupRun(t),
+	}
+
+	vcrTest(t, resource.TestCase{
+		PreCheck:     func() { testAccPreCheck(t) },
+		Providers:    testAccProviders,
+		CheckDestroy: testAccSqlDatabaseInstanceDestroyProducer(t),
+		Steps: []resource.TestStep{
+			{
+				Config: testAccSqlDatabaseInstance_restoreFromBackup(context),
+			},
+			{
+				ResourceName:            "google_sql_database_instance.instance",
+				ImportState:             true,
+				ImportStateVerify:       true,
+				ImportStateVerifyIgnore: []string{"deletion_protection", "restore_backup_context"},
+			},
+		},
+	})
+}
+
+func TestAccSqlDatabaseInstance_backupUpdate(t *testing.T) {
+	// Sqladmin client
+	skipIfVcr(t)
+	t.Parallel()
+
+	context := map[string]interface{}{
+		"random_suffix":    randString(t, 10),
+		"original_db_name": BootstrapSharedSQLInstanceBackupRun(t),
+	}
+
+	vcrTest(t, resource.TestCase{
+		PreCheck:     func() { testAccPreCheck(t) },
+		Providers:    testAccProviders,
+		CheckDestroy: testAccSqlDatabaseInstanceDestroyProducer(t),
+		Steps: []resource.TestStep{
+			{
+				Config: testAccSqlDatabaseInstance_beforeBackup(context),
+			},
+			{
+				ResourceName:            "google_sql_database_instance.instance",
+				ImportState:             true,
+				ImportStateVerify:       true,
+				ImportStateVerifyIgnore: []string{"deletion_protection"},
+			},
+			{
+				Config: testAccSqlDatabaseInstance_restoreFromBackup(context),
+			},
+			{
+				ResourceName:            "google_sql_database_instance.instance",
+				ImportState:             true,
+				ImportStateVerify:       true,
+				ImportStateVerifyIgnore: []string{"deletion_protection", "restore_backup_context"},
+			},
+		},
+	})
+}
+
 func testAccSqlDatabaseInstanceDestroyProducer(t *testing.T) func(s *terraform.State) error {
 	return func(s *terraform.State) error {
 		for _, rs := range s.RootModule().Resources {
@@ -1153,3 +1218,51 @@ resource "google_sql_database_instance" "instance" {
 }
 `, masterID, pointInTimeRecoveryEnabled)
 }
+
+func testAccSqlDatabaseInstance_beforeBackup(context map[string]interface{}) string {
+	return Nprintf(`
+resource "google_sql_database_instance" "instance" {
+  name             = "tf-test-%{random_suffix}"
+  database_version = "POSTGRES_11"
+  region           = "us-central1"
+
+  settings {
+	tier = "db-f1-micro"
+	backup_configuration {
+		enabled            = "false"
+	}
+  }
+
+  deletion_protection = false
+}
+`, context)
+}
+
+func testAccSqlDatabaseInstance_restoreFromBackup(context map[string]interface{}) string {
+	return Nprintf(`
+resource "google_sql_database_instance" "instance" {
+  name             = "tf-test-%{random_suffix}"
+  database_version = "POSTGRES_11"
+  region           = "us-central1"
+
+  settings {
+	tier = "db-f1-micro"
+	backup_configuration {
+		enabled            = "false"
+	}
+  }
+
+  restore_backup_context {
+    backup_run_id = data.google_sql_backup_run.backup.backup_id
+    instance_id = data.google_sql_backup_run.backup.instance
+  }
+
+  deletion_protection = false
+}
+
+data "google_sql_backup_run" "backup" {
+	instance = "%{original_db_name}"
+	most_recent = true
+}
+`, context)
+}

website/docs/r/sql_database_instance.html.markdown

@@ -234,6 +234,11 @@ includes an up-to-date reference of supported versions.
 * `deletion_protection` - (Optional, Default: `true` ) Whether or not to allow Terraform to destroy the instance. Unless this field is set to false
 in Terraform state, a `terraform destroy` or `terraform apply` command that deletes the instance will fail.
 
+* `restore_backup_context` - (optional) The context needed to restore the database to a backup run. This field will
+    cause Terraform to trigger the database to restore from the backup run indicated. The configuration is detailed below.
+    **NOTE:** Restoring from a backup is an imperative action and not recommended via Terraform. Adding or modifying this
+    block during resource creation/update will trigger the restore action after the resource is created/updated. 
+
 The required `settings` block supports:
 
 * `tier` - (Required) The machine type to use. See [tiers](https://cloud.google.com/sql/docs/admin-api/v1beta4/tiers)
@@ -373,6 +378,17 @@ to work, cannot be updated, and supports:
 * `verify_server_certificate` - (Optional) True if the master's common name
     value is checked during the SSL handshake.
 
+The optional `restore_backup_context` block supports:
+**NOTE:** Restoring from a backup is an imperative action and not recommended via Terraform. Adding or modifying this
+block during resource creation/update will trigger the restore action after the resource is created/updated. 
+
+* `backup_run_id` - (Required) The ID of the backup run to restore from.
+
+* `instance_id` - (Optional) The ID of the instance that the backup was taken from. If left empty,
+    this instance's ID will be used.
+
+* `project` - (Optional) The full project ID of the source instance.`
+
 ## Attributes Reference
 
 In addition to the arguments listed above, the following computed attributes are