ScaleIO Driver: Backup volume via snapshot

When a volume is in-use, the ScaleIO driver can achieve the backup of
that volume through creating a temp snapshot, and then backing-up the
snapshot.

Change-Id: I6330cb1b6644de5f470b198f035933ff676c1bce

cinder/tests/unit/volume/drivers/dell_emc/scaleio/test_initialize_connection_snapshot.py

@@ -0,0 +1,102 @@
+# Copyright (c) 2017 Dell Inc. or its subsidiaries.
+# All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+import mock
+
+from cinder import context
+from cinder.tests.unit import fake_constants as fake
+from cinder.tests.unit import fake_snapshot
+from cinder.tests.unit import fake_volume
+from cinder.tests.unit.volume.drivers.dell_emc import scaleio
+
+
+class TestInitializeConnectionSnapshot(scaleio.TestScaleIODriver):
+
+    def setUp(self):
+        super(TestInitializeConnectionSnapshot, self).setUp()
+        self.snapshot_id = 'SNAPID'
+        self.ctx = context.RequestContext('fake', 'fake', auth_token=True)
+        self.fake_path = '/fake/path/vol-xx'
+        self.volume = fake_volume.fake_volume_obj(
+            self.ctx, **{'provider_id': fake.PROVIDER_ID})
+        self.connector = {}
+
+    def test_backup_can_use_snapshots(self):
+        """Make sure the driver can use snapshots for backup."""
+        use_snaps = self.driver.backup_use_temp_snapshot()
+        self.assertTrue(use_snaps)
+
+    def test_initialize_connection_without_size(self):
+        """Test initializing when we do not know the snapshot size.
+
+        ScaleIO can determine QOS specs based upon volume/snapshot size
+        The QOS keys should always be returned
+        """
+        snapshot = fake_snapshot.fake_snapshot_obj(
+            self.ctx, **{'volume': self.volume,
+                         'provider_id': self.snapshot_id})
+        props = self.driver.initialize_connection_snapshot(
+            snapshot,
+            self.connector)
+        # validate the volume type
+        self.assertEqual(props['driver_volume_type'], 'scaleio')
+        # make sure a volume name and id exist
+        self.assertIsNotNone(props['data']['scaleIO_volname'])
+        self.assertEqual(self.snapshot_id,
+                         props['data']['scaleIO_volume_id'])
+        # make sure QOS properties are set
+        self.assertTrue('iopsLimit' in props['data'])
+
+    def test_initialize_connection_with_size(self):
+        """Test initializing when we know the snapshot size.
+
+        ScaleIO can determine QOS specs based upon volume/snapshot size
+        The QOS keys should always be returned
+        """
+        snapshot = fake_snapshot.fake_snapshot_obj(
+            self.ctx, **{'volume': self.volume,
+                         'provider_id': self.snapshot_id,
+                         'volume_size': 8})
+        props = self.driver.initialize_connection_snapshot(
+            snapshot,
+            self.connector)
+        # validate the volume type
+        self.assertEqual(props['driver_volume_type'], 'scaleio')
+        # make sure a volume name and id exist
+        self.assertIsNotNone(props['data']['scaleIO_volname'])
+        self.assertEqual(self.snapshot_id,
+                         props['data']['scaleIO_volume_id'])
+        # make sure QOS properties are set
+        self.assertTrue('iopsLimit' in props['data'])
+
+    def test_qos_specs(self):
+        """Ensure QOS specs are honored if present."""
+        qos = {'maxIOPS': 1000, 'maxBWS': 2048}
+        snapshot = fake_snapshot.fake_snapshot_obj(
+            self.ctx, **{'volume': self.volume,
+                         'provider_id': self.snapshot_id,
+                         'volume_size': 8})
+        extraspecs = {}
+        self.driver._get_volumetype_qos = mock.MagicMock()
+        self.driver._get_volumetype_qos.return_value = qos
+        self.driver._get_volumetype_extraspecs = mock.MagicMock()
+        self.driver._get_volumetype_extraspecs.return_value = extraspecs
+
+        props = self.driver.initialize_connection_snapshot(
+            snapshot,
+            self.connector)
+
+        self.assertEqual(1000, int(props['data']['iopsLimit']))
+        self.assertEqual(2048, int(props['data']['bandwidthLimit']))

cinder/volume/drivers/dell_emc/scaleio/driver.py

@@ -863,30 +863,44 @@ class ScaleIODriver(driver.VolumeDriver):
         return self._delete_volume(snap_id)
 
     def initialize_connection(self, volume, connector, **kwargs):
-        """Initializes the connection and returns connection info.
+        return self._initialize_connection(volume, connector, volume.size)
+
+    def _initialize_connection(self, vol_or_snap, connector, vol_size):
+        """Initializes a connection and returns connection info.
 
         The scaleio driver returns a driver_volume_type of 'scaleio'.
         """
 
-        LOG.debug("Connector is %s.", connector)
+        try:
+            ip = connector['ip']
+        except Exception:
+            ip = 'unknown'
+
+        LOG.debug("Initializing connection for %(vol)s, "
+                  "to SDC at %(sdc)s",
+                  {'vol': vol_or_snap.id,
+                   'sdc': ip})
+
         connection_properties = dict(self.connection_properties)
 
-        volname = self._id_to_base64(volume.id)
+        volname = self._id_to_base64(vol_or_snap.id)
         connection_properties['scaleIO_volname'] = volname
-        connection_properties['scaleIO_volume_id'] = volume.provider_id
-        extra_specs = self._get_volumetype_extraspecs(volume)
-        qos_specs = self._get_volumetype_qos(volume)
-        storage_type = extra_specs.copy()
-        storage_type.update(qos_specs)
-        LOG.info("Volume type is %s.", storage_type)
-        round_volume_size = self._round_to_num_gran(volume.size)
-        iops_limit = self._get_iops_limit(round_volume_size, storage_type)
-        bandwidth_limit = self._get_bandwidth_limit(round_volume_size,
-                                                    storage_type)
-        LOG.info("iops limit is %s", iops_limit)
-        LOG.info("bandwidth limit is %s", bandwidth_limit)
-        connection_properties['iopsLimit'] = iops_limit
-        connection_properties['bandwidthLimit'] = bandwidth_limit
+        connection_properties['scaleIO_volume_id'] = vol_or_snap.provider_id
+
+        if vol_size is not None:
+            extra_specs = self._get_volumetype_extraspecs(vol_or_snap)
+            qos_specs = self._get_volumetype_qos(vol_or_snap)
+            storage_type = extra_specs.copy()
+            storage_type.update(qos_specs)
+            round_volume_size = self._round_to_num_gran(vol_size)
+            iops_limit = self._get_iops_limit(round_volume_size, storage_type)
+            bandwidth_limit = self._get_bandwidth_limit(round_volume_size,
+                                                        storage_type)
+            LOG.info("iops limit is %s", iops_limit)
+            LOG.info("bandwidth limit is %s", bandwidth_limit)
+            connection_properties['iopsLimit'] = iops_limit
+            connection_properties['bandwidthLimit'] = bandwidth_limit
+
         return {'driver_volume_type': 'scaleio',
                 'data': connection_properties}
 
@@ -940,7 +954,22 @@ class ScaleIODriver(driver.VolumeDriver):
             raise exception.InvalidInput(reason=msg)
 
     def terminate_connection(self, volume, connector, **kwargs):
-        LOG.debug("scaleio driver terminate connection.")
+        self._terminate_connection(volume, connector)
+
+    def _terminate_connection(self, volume_or_snap, connector):
+        """Terminate connection to a volume or snapshot
+
+        With ScaleIO, snaps and volumes are terminated identically
+        """
+        try:
+            ip = connector['ip']
+        except Exception:
+            ip = 'unknown'
+
+        LOG.debug("Terminating connection for %(vol)s, "
+                  "to SDC at %(sdc)s",
+                  {'vol': volume_or_snap.id,
+                   'sdc': ip})
 
     def _update_volume_stats(self):
         stats = {}
@@ -1812,3 +1841,28 @@ class ScaleIODriver(driver.VolumeDriver):
     def check_for_export(self, context, volume_id):
         """Make sure volume is exported."""
         pass
+
+    def initialize_connection_snapshot(self, snapshot, connector, **kwargs):
+        # return self._initialize_connection(snapshot, connector)
+        """Initializes a connection and returns connection info."""
+        try:
+            vol_size = snapshot['volume_size']
+        except Exception:
+            vol_size = None
+
+        return self._initialize_connection(snapshot, connector, vol_size)
+
+    def terminate_connection_snapshot(self, snapshot, connector, **kwargs):
+        """Terminates a connection to a snapshot."""
+        return self._terminate_connection(snapshot, connector)
+
+    def create_export_snapshot(self, context, volume, connector):
+        """Driver entry point to get the export info for a snapshot."""
+        pass
+
+    def remove_export_snapshot(self, context, volume):
+        """Driver entry point to remove an export for a snapshot."""
+        pass
+
+    def backup_use_temp_snapshot(self):
+        return True

releasenotes/notes/scaleio-backup-via-snapshot-8e75aa3f4570e17c.yaml

@@ -0,0 +1,4 @@
+---
+features:
+  - Add support to backup volume using snapshot in the Unity driver,
+    which enables backing up of volumes that are in-use.