Add revert to snapshot support in VxFlex OS driver

Add support for reverting to snapshot in VxFlex OS driver.

Implements: blueprint vxflexos-revert-to-snapshot
Change-Id: I0ddde05a6270e06e1aee7e1e3bd5de34cc25eb3b

cinder/tests/unit/volume/drivers/dell_emc/vxflexos/test_revert_volume_to_snapshot.py

@@ -0,0 +1,104 @@
+# Copyright (c) 2020 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.
+
+from unittest import mock
+
+from cinder import context
+from cinder import exception
+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 vxflexos
+
+
+class TestRevertVolume(vxflexos.TestVxFlexOSDriver):
+    """Test cases for ``VxFlexOSDriver.revert_to_snapshot()``"""
+
+    def setUp(self):
+        """Setup a test case environment.
+
+        Creates a fake volume object and sets up the required API responses.
+        """
+
+        super(TestRevertVolume, self).setUp()
+        ctx = context.RequestContext('fake', 'fake', auth_token=True)
+        host = 'host@backend#{}:{}'.format(
+            self.PROT_DOMAIN_NAME,
+            self.STORAGE_POOL_NAME)
+        self.volume = fake_volume.fake_volume_obj(
+            ctx, **{'provider_id': fake.PROVIDER_ID, 'host': host,
+                    'volume_type_id': fake.VOLUME_TYPE_ID,
+                    'size': 8})
+        self.snapshot = fake_snapshot.fake_snapshot_obj(
+            ctx, **{'volume_id': self.volume.id,
+                    'volume_size': self.volume.size}
+        )
+        self.HTTPS_MOCK_RESPONSES = {
+            self.RESPONSE_MODE.Valid: {
+                'instances/Volume::{}/action/overwriteVolumeContent'.format(
+                    self.volume.provider_id
+                ): {},
+            },
+            self.RESPONSE_MODE.Invalid: {
+                'version': "2.6",
+            },
+            self.RESPONSE_MODE.BadStatus: {
+                'instances/Volume::{}/action/overwriteVolumeContent'.format(
+                    self.volume.provider_id
+                ): self.BAD_STATUS_RESPONSE
+            },
+        }
+
+        self.volume_is_replicated_mock = self.mock_object(
+            self.volume, 'is_replicated',
+            return_value=False
+        )
+
+    def test_revert_to_snapshot(self):
+        self.driver.revert_to_snapshot(None, self.volume, self.snapshot)
+
+    def test_revert_to_snapshot_badstatus_response(self):
+        self.set_https_response_mode(self.RESPONSE_MODE.BadStatus)
+        self.assertRaises(exception.VolumeBackendAPIException,
+                          self.driver.revert_to_snapshot,
+                          None, self.volume, self.snapshot)
+
+    def test_revert_to_snapshot_use_generic(self):
+        self.set_https_response_mode(self.RESPONSE_MODE.Invalid)
+        self.assertRaises(NotImplementedError,
+                          self.driver.revert_to_snapshot,
+                          None, self.volume, self.snapshot)
+
+    def test_revert_to_snapshot_replicated_volume(self):
+        self.volume_is_replicated_mock.return_value = True
+        self.assertRaisesRegexp(
+            exception.InvalidVolume,
+            'Reverting replicated volume is not allowed.',
+            self.driver.revert_to_snapshot,
+            None, self.volume, self.snapshot
+        )
+
+    def test_revert_to_snapshot_size_not_equal(self):
+        patched_volume = mock.MagicMock()
+        patched_volume.id = self.volume.id
+        patched_volume.size = 16
+        patched_volume.is_replicated.return_value = False
+        self.assertRaisesRegexp(
+            exception.InvalidVolume,
+            ('Volume %s size is not equal to snapshot %s size.' %
+             (self.volume.id, self.snapshot.id)),
+            self.driver.revert_to_snapshot,
+            None, patched_volume, self.snapshot
+        )

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

@@ -89,9 +89,10 @@ class VxFlexOSDriver(driver.VolumeDriver):
           3.5.0 - Add support for VxFlex OS 3.5.x
           3.5.1 - Add volume replication v2.1 support for VxFlex OS 3.5.x
           3.5.2 - Add volume migration support
+          3.5.3 - Add revert volume to snapshot support
     """
 
-    VERSION = "3.5.2"
+    VERSION = "3.5.3"
     # ThirdPartySystems wiki
     CI_WIKI_NAME = "DellEMC_VxFlexOS_CI"
 
@@ -1502,6 +1503,33 @@ class VxFlexOSDriver(driver.VolumeDriver):
             location = new_volume.provider_location
         return {"_name_id": name_id, "provider_location": location}
 
+    def revert_to_snapshot(self, context, volume, snapshot):
+        """Revert VxFlex OS volume to the specified snapshot."""
+
+        LOG.info("Revert volume %(vol_id)s to snapshot %(snap_id)s.",
+                 {"vol_id": volume.id, "snap_id": snapshot.id})
+
+        client = self._get_client()
+
+        if not flex_utils.version_gte(client.query_rest_api_version(), "3.0"):
+            LOG.debug("VxFlex OS versions less than v3.0 do not "
+                      "support reverting volume to snapshot. "
+                      "Falling back to generic revert to snapshot method.")
+            raise NotImplementedError
+        elif volume.is_replicated():
+            msg = _("Reverting replicated volume is not allowed.")
+            LOG.error(msg)
+            raise exception.InvalidVolume(reason=msg)
+        elif snapshot.volume_size != volume.size:
+            msg = (_("Volume %(vol_id)s size is not equal to snapshot "
+                     "%(snap_id)s size. Revert to snapshot operation is not "
+                     "allowed.") %
+                   {"vol_id": volume.id, "snap_id": snapshot.id})
+            LOG.error(msg)
+            raise exception.InvalidVolume(reason=msg)
+
+        client.overwrite_volume_content(volume, snapshot)
+
     def _query_vxflexos_volume(self, volume, existing_ref):
         type_id = volume.get("volume_type_id")
         if "source-id" not in existing_ref:

cinder/volume/drivers/dell_emc/vxflexos/rest_client.py

@@ -686,3 +686,20 @@ class RestClient(object):
                 LOG.error(msg)
                 raise exception.VolumeBackendAPIException(msg)
         return response
+
+    def overwrite_volume_content(self, volume, snapshot):
+        url = "/instances/Volume::%(vol_id)s/action/overwriteVolumeContent"
+
+        params = {"srcVolumeId": snapshot.provider_id}
+        r, response = self.execute_vxflexos_post_request(
+            url,
+            params=params,
+            vol_id=volume.provider_id
+        )
+        if r.status_code != http_client.OK:
+            msg = (_("Failed to revert volume %(vol_id)s to snapshot "
+                     "%(snap_id)s: %(err)s.") % {"vol_id": volume.id,
+                                                 "snap_id": snapshot.id,
+                                                 "err": response["message"]})
+            LOG.error(msg)
+            raise exception.VolumeBackendAPIException(msg)

doc/source/configuration/block-storage/drivers/dell-emc-vxflex-driver.rst

@@ -73,6 +73,8 @@ Supported operations
 
 * Create a volume from a snapshot
 
+* Revert a volume to a snapshot
+
 * Copy an image to a volume
 
 * Copy a volume to an image

doc/source/reference/support-matrix.ini

@@ -739,7 +739,7 @@ driver.dell_emc_unity=complete
 driver.dell_emc_vmax_af=complete
 driver.dell_emc_vmax_3=complete
 driver.dell_emc_vnx=complete
-driver.dell_emc_vxflexos=missing
+driver.dell_emc_vxflexos=complete
 driver.dell_emc_xtremio=missing
 driver.fujitsu_eternus=missing
 driver.hpe_3par=complete

releasenotes/notes/vxflexos-revert-to-snapshot-a90c40ec476cc2bd.yaml

@@ -0,0 +1,4 @@
+---
+features:
+  - |
+    VxFlex OS driver now supports storage-assisted revert volume to snapshot.