Add cinder snapshot custom constraint

Add cinder snapshot custom constraint to validate
the existent of the snapshot not wait creation.

Change-Id: I4140dfc212eeb4830632c8450e8c8faad3d165f6
Implements: blueprint cinder-custom-constraints

heat/common/exception.py

@@ -240,6 +240,10 @@ class VolumeNotFound(HeatException):
     msg_fmt = _("The Volume (%(volume)s) could not be found.")
 
 
+class VolumeSnapshotNotFound(HeatException):
+    msg_fmt = _("The VolumeSnapshot (%(snapshot)s) could not be found.")
+
+
 class PhysicalResourceNameAmbiguity(HeatException):
     msg_fmt = _(
         "Multiple physical resources were found with name (%(name)s).")

heat/engine/clients/os/cinder.py

@@ -94,6 +94,14 @@ class CinderClientPlugin(client_plugin.ClientPlugin):
                      {'volume': volume, 'ex': ex})
             raise exception.VolumeNotFound(volume=volume)
 
+    def get_volume_snapshot(self, snapshot):
+        try:
+            return self.client().volume_snapshots.get(snapshot)
+        except exceptions.NotFound as ex:
+            LOG.info(_LI('VolumeSnapshot (%(snapshot)s) not found: %(ex)s'),
+                     {'snapshot': snapshot, 'ex': ex})
+            raise exception.VolumeSnapshotNotFound(snapshot=snapshot)
+
     def is_not_found(self, ex):
         return isinstance(ex, exceptions.NotFound)
 
@@ -111,3 +119,11 @@ class VolumeConstraint(constraints.BaseCustomConstraint):
 
     def validate_with_client(self, client, volume):
         client.client_plugin('cinder').get_volume(volume)
+
+
+class VolumeSnapshotConstraint(constraints.BaseCustomConstraint):
+
+    expected_exceptions = (exception.VolumeSnapshotNotFound,)
+
+    def validate_with_client(self, client, snapshot):
+        client.client_plugin('cinder').get_volume_snapshot(snapshot)

heat/tests/test_cinder_client.py

@@ -47,6 +47,20 @@ class CinderClientPluginTests(common.HeatTestCase):
 
         self.m.VerifyAll()
 
+    def test_get_snapshot(self):
+        """Tests the get_volume_snapshot function."""
+        snapshot_id = str(uuid.uuid4())
+        my_snapshot = self.m.CreateMockAnything()
+        self.cinder_client.volume_snapshots = self.m.CreateMockAnything()
+        self.cinder_client.volume_snapshots.get(snapshot_id).MultipleTimes().\
+            AndReturn(my_snapshot)
+        self.m.ReplayAll()
+
+        self.assertEqual(my_snapshot,
+                         self.cinder_plugin.get_volume_snapshot(snapshot_id))
+
+        self.m.VerifyAll()
+
 
 class VolumeConstraintTest(common.HeatTestCase):
 
@@ -66,3 +80,23 @@ class VolumeConstraintTest(common.HeatTestCase):
         self.mock_get_volume.side_effect = exception.VolumeNotFound(
             volume='bar')
         self.assertFalse(self.constraint.validate("bar", self.ctx))
+
+
+class VolumeSnapshotConstraintTest(common.HeatTestCase):
+
+    def setUp(self):
+        super(VolumeSnapshotConstraintTest, self).setUp()
+        self.ctx = utils.dummy_context()
+        self.mock_get_snapshot = mock.Mock()
+        self.ctx.clients.client_plugin(
+            'cinder').get_volume_snapshot = self.mock_get_snapshot
+        self.constraint = cinder.VolumeSnapshotConstraint()
+
+    def test_validation(self):
+        self.mock_get_snapshot.return_value = 'snapshot'
+        self.assertTrue(self.constraint.validate("foo", self.ctx))
+
+    def test_validation_error(self):
+        self.mock_get_snapshot.side_effect = exception.VolumeSnapshotNotFound(
+            snapshot='bar')
+        self.assertFalse(self.constraint.validate("bar", self.ctx))

setup.cfg

@@ -59,6 +59,7 @@ heat.constraints =
     nova.server = heat.engine.clients.os.nova:ServerConstraint
     nova.keypair = heat.engine.clients.os.nova:KeypairConstraint
     cinder.volume = heat.engine.clients.os.cinder:VolumeConstraint
+    cinder.snapshot = heat.engine.clients.os.cinder:VolumeSnapshotConstraint
 
 heat.stack_lifecycle_plugins =