VMware: Revert to snapshot

Adding support for revert-to-snapshot for COW based snapshot
in VMDK driver.

Change-Id: I240d8d6f1745f9611855e6f6897697b5a0748ef9

cinder/tests/unit/volume/drivers/vmware/test_vmware_vmdk.py

@@ -3051,6 +3051,48 @@ class VMwareVcVmdkDriverTestCase(test.TestCase):
         vops.move_backing_to_folder.assert_called_once_with(backing,
                                                             new_folder)
 
+    @mock.patch.object(VMDK_DRIVER, 'volumeops')
+    def test_revert_to_snapshot_with_no_backing(self, vops):
+        vops.get_backing.return_value = None
+
+        volume = self._create_volume_obj()
+        snapshot = fake_snapshot.fake_snapshot_obj(self._context,
+                                                   volume=volume)
+        self._driver.revert_to_snapshot(
+            mock.sentinel.context, volume, snapshot)
+
+        vops.get_backing.assert_called_once_with(volume.name)
+        vops.revert_to_snapshot.assert_not_called()
+
+    @mock.patch.object(VMDK_DRIVER, 'volumeops')
+    def test_revert_to_snapshot_template_format(self, vops):
+        volume = self._create_volume_obj()
+        loc = '/test-dc/foo'
+        snapshot = fake_snapshot.fake_snapshot_obj(self._context,
+                                                   volume=volume,
+                                                   provider_location=loc)
+        self.assertRaises(cinder_exceptions.InvalidSnapshot,
+                          self._driver.revert_to_snapshot,
+                          mock.sentinel.context,
+                          volume,
+                          snapshot)
+        vops.revert_to_snapshot.assert_not_called()
+
+    @mock.patch.object(VMDK_DRIVER, 'volumeops')
+    def test_revert_to_snapshot(self, vops):
+        backing = mock.sentinel.backing
+        vops.get_backing.return_value = backing
+
+        volume = self._create_volume_obj()
+        snapshot = fake_snapshot.fake_snapshot_obj(self._context,
+                                                   volume=volume)
+        self._driver.revert_to_snapshot(
+            mock.sentinel.context, volume, snapshot)
+
+        vops.get_backing.assert_called_once_with(volume.name)
+        vops.revert_to_snapshot.assert_called_once_with(backing,
+                                                        snapshot.name)
+
 
 @ddt.ddt
 class ImageDiskTypeTest(test.TestCase):

cinder/tests/unit/volume/drivers/vmware/test_vmware_volumeops.py

@@ -947,6 +947,33 @@ class VolumeOpsTestCase(test.TestCase):
                                                snapshot, removeChildren=False)
             self.session.wait_for_task.assert_called_once_with(task)
 
+    @mock.patch('cinder.volume.drivers.vmware.volumeops.VMwareVolumeOps.'
+                'get_snapshot')
+    def test_revert_to_snapshot_with_missing_snapshot(self, get_snapshot):
+        get_snapshot.return_value = None
+
+        backing = mock.sentinel.backing
+        self.assertRaises(vmdk_exceptions.SnapshotNotFoundException,
+                          self.vops.revert_to_snapshot, backing, 'foo')
+        get_snapshot.assert_called_once_with(backing, 'foo')
+
+    @mock.patch('cinder.volume.drivers.vmware.volumeops.VMwareVolumeOps.'
+                'get_snapshot')
+    def test_revert_to_snapshot(self, get_snapshot):
+        snapshot = mock.sentinel.snapshot
+        get_snapshot.return_value = snapshot
+
+        task = mock.sentinel.task
+        self.session.invoke_api.return_value = task
+
+        backing = mock.sentinel.backing
+        self.vops.revert_to_snapshot(backing, 'foo')
+
+        get_snapshot.assert_called_once_with(backing, 'foo')
+        self.session.invoke_api.assert_called_once_with(
+            self.session.vim, 'RevertToSnapshot_Task', snapshot)
+        self.session.wait_for_task.assert_called_once_with(task)
+
     def test_get_folder(self):
         folder = mock.sentinel.folder
         backing = mock.sentinel.backing

cinder/volume/drivers/vmware/exceptions.py

@@ -60,3 +60,8 @@ class NoValidHostException(exceptions.VMwareDriverException):
 class TemplateNotFoundException(exceptions.VMwareDriverException):
     """Thrown when template cannot be found."""
     msg_fmt = _("Template cannot be found at path: %(path)s.")
+
+
+class SnapshotNotFoundException(exceptions.VMwareDriverException):
+    """Thrown when the backend snapshot cannot be found."""
+    msg_fmt = _("Snapshot: %(name)s not found.")

cinder/volume/drivers/vmware/vmdk.py

@@ -2142,3 +2142,17 @@ class VMwareVcVmdkDriver(driver.VolumeDriver):
             dc = self.volumeops.get_dc(backing)
             new_folder = self._get_volume_group_folder(dc, new_project)
             self.volumeops.move_backing_to_folder(backing, new_folder)
+
+    def revert_to_snapshot(self, context, volume, snapshot):
+        inv_path = snapshot.provider_location
+        is_template = inv_path is not None
+        if is_template:
+            LOG.error("Revert to template based snapshot is not supported.")
+            raise exception.InvalidSnapshot("Cannot revert to template "
+                                            "based snapshot")
+
+        backing = self.volumeops.get_backing(volume.name)
+        if not backing:
+            LOG.debug("Backing does not exist for volume.", resource=volume)
+        else:
+            self.volumeops.revert_to_snapshot(backing, snapshot.name)

cinder/volume/drivers/vmware/volumeops.py

@@ -1048,6 +1048,20 @@ class VMwareVolumeOps(object):
         LOG.info("Successfully deleted snapshot: %(name)s of backing: "
                  "%(backing)s.", {'backing': backing, 'name': name})
 
+    def revert_to_snapshot(self, backing, name):
+        LOG.debug("Revert to snapshot: %(name)s of backing: %(backing)s.",
+                  {'name': name, 'backing': backing})
+
+        snapshot = self.get_snapshot(backing, name)
+        if not snapshot:
+            raise vmdk_exceptions.SnapshotNotFoundException(
+                name=name)
+
+        task = self._session.invoke_api(self._session.vim,
+                                        'RevertToSnapshot_Task',
+                                        snapshot)
+        self._session.wait_for_task(task)
+
     def _get_folder(self, backing):
         """Get parent folder of the backing.
 

releasenotes/notes/vmware-vmdk-revert-to-snapshot-ee3d638565649f44.yaml

@@ -0,0 +1,5 @@
+---
+features:
+  - |
+    Added support for revert-to-snapshot in the VMware VMDK driver.
+