Add test for creating volume from source

This patch adds a test to create a new volume from source.
We also include code changes to pass the right size i.e. either
size passed by the user via --size argument or the source volume
size. This case is already handled at the API layer[1] but it
helps being consistent with passing the right size value as in case
of creating a volume from snapshot or backup.

[1] 7c1a5ce7b1/cinder/api/v3/volumes.py (L381-L382)

Change-Id: Idc71636dad6bb678fe24f19b0836d2e9bd92d7d2

openstackclient/tests/unit/volume/v2/test_volume.py

@@ -398,6 +398,43 @@ class TestVolumeCreate(TestVolume):
                                 parsed_args)
         self.assertIn("--os-volume-api-version 3.47 or greater", str(exc))
 
+    def test_volume_create_with_source_volume(self):
+        source_vol = "source_vol"
+        arglist = [
+            '--source', self.new_volume.id,
+            source_vol,
+        ]
+        verifylist = [
+            ('source', self.new_volume.id),
+            ('name', source_vol),
+        ]
+        parsed_args = self.check_parser(self.cmd, arglist, verifylist)
+
+        self.volumes_mock.get.return_value = self.new_volume
+
+        # In base command class ShowOne in cliff, abstract method take_action()
+        # returns a two-part tuple with a tuple of column names and a tuple of
+        # data to be shown.
+        columns, data = self.cmd.take_action(parsed_args)
+
+        self.volumes_mock.create.assert_called_once_with(
+            size=self.new_volume.size,
+            snapshot_id=None,
+            name=source_vol,
+            description=None,
+            volume_type=None,
+            availability_zone=None,
+            metadata=None,
+            imageRef=None,
+            source_volid=self.new_volume.id,
+            consistencygroup_id=None,
+            scheduler_hints=None,
+            backup_id=None,
+        )
+
+        self.assertEqual(self.columns, columns)
+        self.assertCountEqual(self.datalist, data)
+
     def test_volume_create_with_bootable_and_readonly(self):
         arglist = [
             '--bootable',

openstackclient/volume/v2/volume.py

@@ -183,6 +183,11 @@ class CreateVolume(command.ShowOne):
 
     def take_action(self, parsed_args):
         _check_size_arg(parsed_args)
+        # size is validated in the above call to
+        # _check_size_arg where we check that size
+        # should be passed if we are not creating a
+        # volume from snapshot, backup or source volume
+        size = parsed_args.size
 
         volume_client = self.app.client_manager.volume
         image_client = self.app.client_manager.image
@@ -195,9 +200,11 @@ class CreateVolume(command.ShowOne):
 
         source_volume = None
         if parsed_args.source:
-            source_volume = utils.find_resource(
+            source_volume_obj = utils.find_resource(
                 volume_client.volumes,
-                parsed_args.source).id
+                parsed_args.source)
+            source_volume = source_volume_obj.id
+            size = max(size or 0, source_volume_obj.size)
 
         consistency_group = None
         if parsed_args.consistency_group:
@@ -210,8 +217,6 @@ class CreateVolume(command.ShowOne):
             image = image_client.find_image(parsed_args.image,
                                             ignore_missing=False).id
 
-        size = parsed_args.size
-
         snapshot = None
         if parsed_args.snapshot:
             snapshot_obj = utils.find_resource(