Add block_device_mapping_get_all_by_instance to virtapi

Add another conductor api method to the virtapi.  This is needed by the
following patch: https://review.openstack.org/#/c/42812

Part of blueprint qemu-assisted-snapshots

Change-Id: I21d0ebe9f83423d504f7626f0d048b31945156d9

nova/compute/manager.py

@@ -379,6 +379,12 @@ class ComputeVirtAPI(virtapi.VirtAPI):
         return self._compute.conductor_api.instance_type_get(context,
                                                              instance_type_id)
 
+    def block_device_mapping_get_all_by_instance(self, context, instance,
+                                                 legacy=True):
+        capi = self._compute.conductor_api
+        return capi.block_device_mapping_get_all_by_instance(context, instance,
+                                                             legacy=legacy)
+
 
 class ComputeManager(manager.SchedulerDependentManager):
     """Manages the running instances from creation to destruction."""

nova/tests/compute/test_virtapi.py

@@ -75,6 +75,10 @@ class VirtAPIBaseTest(test.TestCase, test.APICoverage):
         self.assertExpected('instance_type_get',
                             'fake-instance-type')
 
+    def test_block_device_mapping_get_all_by_instance(self):
+        self.assertExpected('block_device_mapping_get_all_by_instance',
+                            {'uuid': 'fake_uuid'}, legacy=False)
+
 
 class FakeVirtAPITest(VirtAPIBaseTest):
 
@@ -97,13 +101,19 @@ class FakeVirtAPITest(VirtAPIBaseTest):
             # NOTE(danms): FakeVirtAPI will convert the first argument to
             # argument['id'], so expect that in the actual db call
             e_args = tuple([args[0]['id']] + list(args[1:]))
-        elif method in ('test_security_group_get_by_instance'):
+        elif method in ('security_group_get_by_instance',
+                        'block_device_mapping_get_all_by_instance'):
             e_args = tuple([args[0]['uuid']] + list(args[1:]))
         else:
             e_args = args
 
-        getattr(db, db_method)(self.context, *e_args, **kwargs).AndReturn(
-            'it worked')
+        if method in ('block_device_mapping_get_all_by_instance'):
+            e_kwargs = {}
+        else:
+            e_kwargs = kwargs
+
+        getattr(db, db_method)(self.context, *e_args, **e_kwargs).AndReturn(
+                'it worked')
         self.mox.ReplayAll()
         result = getattr(self.virtapi, method)(self.context, *args, **kwargs)
         self.assertEqual(result, 'it worked')

nova/virt/fake.py

@@ -27,6 +27,7 @@ semantics of real hypervisor connections.
 
 from oslo.config import cfg
 
+from nova import block_device
 from nova.compute import power_state
 from nova.compute import task_states
 from nova import db
@@ -490,3 +491,11 @@ class FakeVirtAPI(virtapi.VirtAPI):
 
     def instance_type_get(self, context, instance_type_id):
         return db.instance_type_get(context, instance_type_id)
+
+    def block_device_mapping_get_all_by_instance(self, context, instance,
+                                                 legacy=True):
+        bdms = db.block_device_mapping_get_all_by_instance(context,
+                                                           instance['uuid'])
+        if legacy:
+            bdms = block_device.legacy_mapping(bdms)
+        return bdms

nova/virt/virtapi.py

@@ -90,3 +90,12 @@ class VirtAPI(object):
         :param instance_type_id: the id of the instance type in question
         """
         raise NotImplementedError()
+
+    def block_device_mapping_get_all_by_instance(self, context, instance,
+                                                 legacy=True):
+        """Get block device mappings for an instance
+        :param context: security context
+        :param instance: the instance we're getting bdms for
+        :param legacy: get bdm info in legacy format (or not)
+        """
+        raise NotImplementedError()