Support block_store types where IDs are taken

In an effort to widen support for resource properties that are IDs but
can take the appropriate resource type for that ID, the block_store
service throws a kink into it. The Volume type can contain a Snapshot,
and a Snapshot can contain a Volume. Because of that loop, we can't do
the usual `foo = resource.prop(foo, FooType)`. We can sort of emulate
the behavior users will get out of it in the proxy by doing a type
conversion in the create_volume and create_snapshot methods to support
resource instances being passed in there.

Additionally, Volume can be created from another Volume, but we can't
have a prop refer to its own class, so that problem is solved the same
as above.

Lastly, the Volume resource has two props that can take real types:
image and type.

Change-Id: If8a5b24b05a341ae6bfe9dca6b93429dcfc8f408

openstack/block_store/v2/_proxy.py

@@ -18,6 +18,23 @@ from openstack import proxy
 
 class Proxy(proxy.BaseProxy):
 
+    def _convert_id(self, attrs, value, resource_type):
+        """Convert potential Resource values into IDs
+
+        The structure of Snapshot and Volume resources is such that their
+        Resource subclasses contain properties of each other's types, because
+        a Snapshot can be created of a Volume, and a Volume can be created from
+        a Snapshot. Additionally, a Volume can be created from another
+        Volume, yet the source_volume prop can't refer to the current class.
+        We work around this by simply looking for those Resource types
+        before sending them on.
+        """
+        val = attrs.pop(value, None)
+        if val is not None:
+            if isinstance(val, resource_type):
+                val = val.id
+            attrs[value] = val
+
     def get_snapshot(self, snapshot):
         """Get a single snapshot
 
@@ -41,6 +58,7 @@ class Proxy(proxy.BaseProxy):
         :returns: The results of snapshot creation
         :rtype: :class:`~openstack.volume.v2.snapshot.Snapshot`
         """
+        self._convert_id(attrs, "volume", _volume.Volume)
         return self._create(_snapshot.Snapshot, **attrs)
 
     def delete_snapshot(self, snapshot, ignore_missing=True):
@@ -121,6 +139,8 @@ class Proxy(proxy.BaseProxy):
         :returns: The results of volume creation
         :rtype: :class:`~openstack.volume.v2.volume.Volume`
         """
+        self._convert_id(attrs, "source_volume", _volume.Volume)
+        self._convert_id(attrs, "snapshot", _snapshot.Snapshot)
         return self._create(_volume.Volume, **attrs)
 
     def delete_volume(self, volume, ignore_missing=True):

openstack/block_store/v2/volume.py

@@ -11,6 +11,8 @@
 # under the License.
 
 from openstack.block_store import block_store_service
+from openstack.block_store.v2 import type as _type
+from openstack.image.v2 import image as _image
 from openstack import resource
 
 
@@ -50,9 +52,9 @@ class Volume(resource.Resource):
     size = resource.prop("size", type=int)
     #: The ID of the image from which you want to create the volume.
     #: Required to create a bootable volume.
-    image = resource.prop("imageRef")
+    image = resource.prop("imageRef", type=_image.Image)
     #: The associated volume type.
-    type = resource.prop("volume_type")
+    type = resource.prop("volume_type", type=_type.Type)
     #: Enables or disables the bootable attribute. You can boot an
     #: instance from a bootable volume. *Type: bool*
     bootable = resource.prop("bootable", type=bool)

openstack/tests/unit/block_store/v2/test_proxy.py

@@ -10,6 +10,8 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
+import mock
+
 from openstack.block_store.v2 import _proxy
 from openstack.block_store.v2 import snapshot
 from openstack.block_store.v2 import type
@@ -28,6 +30,16 @@ class TestVolumeProxy(test_proxy_base.TestProxyBase):
     def test_snapshot_create_attrs(self):
         self.verify_create(self.proxy.create_snapshot, snapshot.Snapshot)
 
+    def test_snapshot_create_volume_prop(self):
+        self.proxy._create = mock.Mock()
+
+        id = "12345"
+        vol = volume.Volume({"id": id})
+        self.proxy.create_snapshot(volume=vol)
+
+        kwargs = self.proxy._create.call_args[1]
+        self.assertEqual({"volume": id}, kwargs)
+
     def test_snapshot_delete(self):
         self.verify_delete(self.proxy.delete_snapshot,
                            snapshot.Snapshot, False)
@@ -54,6 +66,18 @@ class TestVolumeProxy(test_proxy_base.TestProxyBase):
     def test_volume_create_attrs(self):
         self.verify_create(self.proxy.create_volume, volume.Volume)
 
+    def test_volume_create_snapshot_prop(self):
+        self.proxy._create = mock.Mock()
+
+        id1 = "12345"
+        id2 = "67890"
+        snap = snapshot.Snapshot({"id": id1})
+        source = volume.Volume({"id": id2})
+        self.proxy.create_volume(snapshot=snap, source_volume=source)
+
+        kwargs = self.proxy._create.call_args[1]
+        self.assertEqual({"snapshot": id1, "source_volume": id2}, kwargs)
+
     def test_volume_delete(self):
         self.verify_delete(self.proxy.delete_volume, volume.Volume, False)
 

openstack/tests/unit/block_store/v2/test_volume.py

@@ -14,7 +14,9 @@ import copy
 
 import testtools
 
+from openstack.block_store.v2 import type
 from openstack.block_store.v2 import volume
+from openstack.image.v2 import image
 
 FAKE_ID = "6685584b-1eac-4da6-b5c3-555430cf68ff"
 
@@ -26,9 +28,10 @@ VOLUME = {
     "bootable": False,
     "created_at": "2014-02-21T19:52:04.949734",
     "description": "something",
-    "volume_type": None,
+    "volume_type": "some_type",
     "snapshot_id": "93c2e2aa-7744-4fd6-a31a-80c4726b08d7",
     "source_volid": None,
+    "image": "some_image",
     "metadata": {},
     "id": FAKE_ID,
     "size": 10
@@ -74,11 +77,12 @@ class TestVolume(testtools.TestCase):
         self.assertEqual(VOLUME["bootable"], sot.bootable)
         self.assertEqual(VOLUME["created_at"], sot.created)
         self.assertEqual(VOLUME["description"], sot.description)
-        self.assertEqual(VOLUME["volume_type"], sot.type)
+        self.assertEqual(type.Type({"id": VOLUME["volume_type"]}), sot.type)
         self.assertEqual(VOLUME["snapshot_id"], sot.snapshot)
         self.assertEqual(VOLUME["source_volid"], sot.source_volume)
         self.assertEqual(VOLUME["metadata"], sot.metadata)
         self.assertEqual(VOLUME["size"], sot.size)
+        self.assertEqual(image.Image({"id": VOLUME["image"]}), sot.image)
 
 
 class TestVolumeDetail(testtools.TestCase):