Add ability to specify backup driver via class name

This patch also deprecates backup driver initialization using module
name.

Change-Id: Id6bee9e7d0da8ead224a04f86fe79ddfb5b286cf
Related-Blueprint: generic-backup-implementation

cinder/backup/manager.py

@@ -60,7 +60,7 @@ LOG = logging.getLogger(__name__)
 
 backup_manager_opts = [
     cfg.StrOpt('backup_driver',
-               default='cinder.backup.drivers.swift',
+               default='cinder.backup.drivers.swift.SwiftBackupDriver',
                help='Driver to use for backups.',),
     cfg.BoolOpt('backup_service_inithost_offload',
                 default=True,
@@ -90,7 +90,6 @@ class BackupManager(manager.ThreadPoolManager):
     target = messaging.Target(version=RPC_API_VERSION)
 
     def __init__(self, *args, **kwargs):
-        self.service = importutils.import_module(self.driver_name)
         self.az = CONF.storage_availability_zone
         self.backup_rpcapi = backup_rpcapi.BackupAPI()
         self.volume_rpcapi = volume_rpcapi.VolumeAPI()
@@ -115,6 +114,23 @@ class BackupManager(manager.ThreadPoolManager):
             return mapper[service]
         return service
 
+    def get_backup_driver(self, context):
+        driver = None
+        try:
+            # TODO(e0ne): remove backward compatibility in S release
+            service = importutils.import_module(self.driver_name)
+            msg = ("Backup driver initialization using module name "
+                   "is deprecated and will be removed in a 'S' "
+                   "release. Please, use classname for backup driver "
+                   "reference in the config.")
+            versionutils.report_deprecated_feature(LOG, msg)
+            driver = service.get_backup_driver(context)
+        except ImportError:
+            driver_class = importutils.import_class(self.driver_name)
+            driver = driver_class(context=context, db=self.db)
+
+        return driver
+
     def _update_backup_error(self, backup, err,
                              status=fields.BackupStatus.ERROR):
         backup.status = status
@@ -133,7 +149,7 @@ class BackupManager(manager.ThreadPoolManager):
             LOG.exception("Problem cleaning incomplete backup operations.")
 
     def _setup_backup_driver(self, ctxt):
-        backup_service = self.service.get_backup_driver(ctxt)
+        backup_service = self.get_backup_driver(ctxt)
         backup_service.check_for_setup_error()
         self.is_initialized = True
         raise loopingcall.LoopingCallDone()
@@ -389,7 +405,7 @@ class BackupManager(manager.ThreadPoolManager):
         self._notify_about_backup_usage(context, backup, "create.end")
 
     def _run_backup(self, context, backup, volume):
-        backup_service = self.service.get_backup_driver(context)
+        backup_service = self.get_backup_driver(context)
 
         properties = utils.brick_get_connector_properties()
         try:
@@ -505,7 +521,7 @@ class BackupManager(manager.ThreadPoolManager):
         self._notify_about_backup_usage(context, backup, "restore.end")
 
     def _run_restore(self, context, backup, volume):
-        backup_service = self.service.get_backup_driver(context)
+        backup_service = self.get_backup_driver(context)
 
         properties = utils.brick_get_connector_properties()
         secure_enabled = (
@@ -569,7 +585,7 @@ class BackupManager(manager.ThreadPoolManager):
                 raise exception.InvalidBackup(reason=err)
 
             try:
-                backup_service = self.service.get_backup_driver(context)
+                backup_service = self.get_backup_driver(context)
                 backup_service.delete_backup(backup)
             except Exception as err:
                 with excutils.save_and_reraise_exception():
@@ -653,7 +669,7 @@ class BackupManager(manager.ThreadPoolManager):
 
         # Call driver to create backup description string
         try:
-            backup_service = self.service.get_backup_driver(context)
+            backup_service = self.get_backup_driver(context)
             driver_info = backup_service.export_record(backup)
             backup_url = backup.encode_record(driver_info=driver_info)
             backup_record['backup_url'] = backup_url
@@ -709,7 +725,7 @@ class BackupManager(manager.ThreadPoolManager):
 
                 # Extract driver specific info and pass it to the driver
                 driver_options = backup_options.pop('driver_info', {})
-                backup_service = self.service.get_backup_driver(context)
+                backup_service = self.get_backup_driver(context)
                 backup_service.import_record(backup, driver_options)
             except Exception as err:
                 msg = six.text_type(err)
@@ -813,7 +829,7 @@ class BackupManager(manager.ThreadPoolManager):
                 if (status == fields.BackupStatus.AVAILABLE
                         and backup['status'] != fields.BackupStatus.RESTORING):
                     # check whether we could verify the backup is ok or not
-                    backup_service = self.service.get_backup_driver(context)
+                    backup_service = self.get_backup_driver(context)
                     if isinstance(backup_service,
                                   driver.BackupDriverWithVerify):
                         backup_service.verify(backup.id)
@@ -878,7 +894,7 @@ class BackupManager(manager.ThreadPoolManager):
 
         :param context: running context
         """
-        backup_service = self.service.get_backup_driver(context)
+        backup_service = self.get_backup_driver(context)
         return backup_service.support_force_delete
 
     def _attach_device(self, ctxt, backup_device,

cinder/db/base.py

@@ -19,6 +19,7 @@
 
 from oslo_config import cfg
 from oslo_utils import importutils
+import six
 
 
 db_driver_opt = cfg.StrOpt('db_driver',
@@ -38,5 +39,10 @@ class Base(object):
         super(Base, self).__init__()
         if not db_driver:
             db_driver = CONF.db_driver
-        self.db = importutils.import_module(db_driver)  # pylint: disable=C0103
+
+        # pylint: disable=C0103
+        if isinstance(db_driver, six.string_types):
+            self.db = importutils.import_module(db_driver)
+        else:
+            self.db = db_driver
         self.db.dispose_engine()

cinder/tests/unit/backup/test_backup.py

@@ -36,7 +36,6 @@ from cinder import objects
 from cinder.objects import fields
 from cinder import test
 from cinder.tests import fake_driver
-from cinder.tests.unit.backup import fake_service_with_verify as fake_service
 from cinder.tests.unit import utils
 from cinder.volume import rpcapi as volume_rpcapi
 
@@ -650,9 +649,9 @@ class BackupTestCase(BaseBackupTest):
         vol_size = 1
         vol_id = self._create_volume_db_entry(size=vol_size)
         backup = self._create_backup_db_entry(volume_id=vol_id,
-                                              parent_id = 'mock')
+                                              parent_id='mock')
 
-        with mock.patch.object(self.backup_mgr.service, 'get_backup_driver') as \
+        with mock.patch.object(self.backup_mgr, 'get_backup_driver') as \
                 mock_get_backup_driver:
             mock_get_backup_driver.return_value.backup.return_value = (
                 {'parent_id': None})
@@ -687,7 +686,7 @@ class BackupTestCase(BaseBackupTest):
         backup = self._create_backup_db_entry(volume_id=vol_id)
         parent_backup = self._create_backup_db_entry(size=vol_size)
 
-        with mock.patch.object(self.backup_mgr.service, 'get_backup_driver') as \
+        with mock.patch.object(self.backup_mgr, 'get_backup_driver') as \
                 mock_get_backup_driver:
             mock_get_backup_driver.return_value.backup.return_value = (
                 {'parent_id': parent_backup.id})
@@ -720,7 +719,7 @@ class BackupTestCase(BaseBackupTest):
         vol_id = self._create_volume_db_entry()
         backup = self._create_backup_db_entry(volume_id=vol_id)
 
-        with mock.patch.object(self.backup_mgr.service, 'get_backup_driver') as \
+        with mock.patch.object(self.backup_mgr, 'get_backup_driver') as \
                 mock_get_backup_driver:
             mock_get_backup_driver.return_value.backup.side_effect = (
                 FakeBackupException('fake'))
@@ -759,7 +758,7 @@ class BackupTestCase(BaseBackupTest):
         backup_service = lambda: None
         backup_service.backup = mock.Mock(
             return_value=mock.sentinel.backup_update)
-        self.backup_mgr.service.get_backup_driver = lambda x: backup_service
+        self.backup_mgr.get_backup_driver = lambda x: backup_service
 
         vol_id = self._create_volume_db_entry()
         backup = self._create_backup_db_entry(volume_id=vol_id)
@@ -1343,7 +1342,7 @@ class BackupTestCase(BaseBackupTest):
         record where the backup driver returns an exception.
         """
         export = self._create_exported_record_entry()
-        backup_driver = self.backup_mgr.service.get_backup_driver(self.ctxt)
+        backup_driver = self.backup_mgr.get_backup_driver(self.ctxt)
         _mock_record_import_class = ('%s.%s.%s' %
                                      (backup_driver.__module__,
                                       backup_driver.__class__.__name__,
@@ -1415,7 +1414,7 @@ class BackupTestCaseWithVerify(BaseBackupTest):
         imported_record = self._create_export_record_db_entry(
             backup_id=backup_id)
         backup_hosts = []
-        backup_driver = self.backup_mgr.service.get_backup_driver(self.ctxt)
+        backup_driver = self.backup_mgr.get_backup_driver(self.ctxt)
         _mock_backup_verify_class = ('%s.%s.%s' %
                                      (backup_driver.__module__,
                                       backup_driver.__class__.__name__,
@@ -1449,7 +1448,7 @@ class BackupTestCaseWithVerify(BaseBackupTest):
         imported_record = self._create_export_record_db_entry(
             backup_id=backup_id)
         backup_hosts = []
-        backup_driver = self.backup_mgr.service.get_backup_driver(self.ctxt)
+        backup_driver = self.backup_mgr.get_backup_driver(self.ctxt)
         _mock_backup_verify_class = ('%s.%s.%s' %
                                      (backup_driver.__module__,
                                       backup_driver.__class__.__name__,
@@ -1481,7 +1480,8 @@ class BackupTestCaseWithVerify(BaseBackupTest):
                                '_map_service_to_driver') as \
                 mock_map_service_to_driver:
             # It should works when the service name is a string
-            mock_map_service_to_driver.return_value = 'swift'
+            backup_driver = 'cinder.tests.unit.backup.fake_service_with_verify'
+            mock_map_service_to_driver.return_value = backup_driver
             self.backup_mgr.reset_status(self.ctxt,
                                          backup,
                                          fields.BackupStatus.AVAILABLE)
@@ -1490,8 +1490,7 @@ class BackupTestCaseWithVerify(BaseBackupTest):
             self.assertEqual(fields.BackupStatus.AVAILABLE,
                              new_backup['status'])
 
-            mock_map_service_to_driver.return_value = \
+            mock_map_service_to_driver.return_value = backup_driver
-                fake_service.get_backup_driver(self.ctxt)
             self.backup_mgr.reset_status(self.ctxt,
                                          backup,
                                          fields.BackupStatus.ERROR)
@@ -1512,7 +1511,7 @@ class BackupTestCaseWithVerify(BaseBackupTest):
         backup = self._create_backup_db_entry(status=fields.BackupStatus.ERROR,
                                               volume_id=volume['id'])
 
-        backup_driver = self.backup_mgr.service.get_backup_driver(self.ctxt)
+        backup_driver = self.backup_mgr.get_backup_driver(self.ctxt)
         _mock_backup_verify_class = ('%s.%s.%s' %
                                      (backup_driver.__module__,
                                       backup_driver.__class__.__name__,

releasenotes/notes/backup-driver-configuration-36357733962dab03.yaml

@@ -0,0 +1,11 @@
+---
+features:
+  - |
+    Add ability to specify backup driver via class name.
+upgrade:
+  - |
+    Operators should change backup driver configuration value to use class
+    name to get backup service working in a 'S' release.
+deprecations:
+  - |
+    Backup driver initialization using module name is deprecated.