Add support for os-assisted-volume-snapshots

This patch adds support for the assisted volume snapshots API extension.
This is used by Cinder to ask Nova to perform a volume snapshot on its
behalf.  It's required when the volume is actually file backed (like
qcow2) and the hypervisor needs to be involved in the snapshot
operation.

Required for blueprint qemu-assisted-snapshots

Change-Id: I50ee9bf92c8de98528638d1724fe35e07bed729e

novaclient/tests/v1_1/contrib/fakes.py

@@ -129,3 +129,9 @@ class FakeHTTPClient(fakes.FakeHTTPClient):
             return (202, {}, {})
         else:
             return (500, {}, {})
+
+    def post_os_assisted_volume_snapshots(self, **kw):
+        return (202, {}, {'snapshot': {'id': 'blah', 'volumeId': '1'}})
+
+    def delete_os_assisted_volume_snapshots_x(self, **kw):
+        return (202, {}, {})

novaclient/tests/v1_1/contrib/test_assisted_volume_snapshots.py

@@ -0,0 +1,41 @@
+# Copyright (C) 2013, Red Hat, Inc.
+#
+#    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.
+
+"""
+Assisted volume snapshots - to be used by Cinder and not end users.
+"""
+
+from novaclient import extension
+from novaclient.tests import utils
+from novaclient.tests.v1_1.contrib import fakes
+from novaclient.v1_1.contrib import assisted_volume_snapshots as assisted_snaps
+
+
+extensions = [
+    extension.Extension(assisted_snaps.__name__.split(".")[-1],
+                        assisted_snaps),
+]
+cs = fakes.FakeClient(extensions=extensions)
+
+
+class AssistedVolumeSnapshotsTestCase(utils.TestCase):
+
+    def test_create_snap(self):
+        res = cs.assisted_volume_snapshots.create('1', {})
+        cs.assert_called('POST', '/os-assisted-volume-snapshots')
+
+    def test_delete_snap(self):
+        res = cs.assisted_volume_snapshots.delete('x', {})
+        cs.assert_called('DELETE',
+                '/os-assisted-volume-snapshots/x?delete_info={}')

novaclient/v1_1/contrib/assisted_volume_snapshots.py

@@ -0,0 +1,48 @@
+# Copyright (C) 2013, Red Hat, Inc.
+#
+#    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.
+
+"""
+Assisted volume snapshots - to be used by Cinder and not end users.
+"""
+
+import json
+
+from novaclient import base
+
+
+class Snapshot(base.Resource):
+    def __repr__(self):
+        return "<Snapshot: %s>" % self.id
+
+    def delete(self):
+        """
+        Delete this snapshot.
+        """
+        self.manager.delete(self)
+
+
+class AssistedSnapshotManager(base.Manager):
+    resource_class = Snapshot
+
+    def create(self, volume_id, create_info):
+        body = {'snapshot': {'volume_id': volume_id,
+                             'create_info': create_info}}
+        return self._create('/os-assisted-volume-snapshots', body, 'snapshot')
+
+    def delete(self, snapshot, delete_info):
+        self._delete("/os-assisted-volume-snapshots/%s?delete_info=%s" % (
+                base.getid(snapshot), json.dumps(delete_info)))
+
+manager_class = AssistedSnapshotManager
+name = 'assisted_volume_snapshots'