Fix Cells RPC API by accepting a RequestSpec arg

Since cells v1 adds a proxy to a call to ComputeTaskAPI for live_migrate
and rebuild_instance, we need to augment the Cells RPC API to accept
the request_spec argument for both methods.

That said, since cells v1 is quite feature-freeze, it's okay to not pass
the RequestSpec down to the pipe because the cell conductor will then
act as if the instance was not having a Spec object, which is a compat
behaviour we want to keep for a very long time.

Closes-Bug: #1550018

Change-Id: I1c2aaedfc83e4e97f53c9c504e4585b1f0510d4b

nova/cells/rpcapi.py

@@ -571,7 +571,12 @@ class CellsAPI(object):
         cctxt.cast(ctxt, 'resize_instance', **msg_args)
 
     def live_migrate_instance(self, ctxt, instance, host_name,
-                              block_migration, disk_over_commit):
+                              block_migration, disk_over_commit,
+                              request_spec=None):
+        # NOTE(sbauza): Since Cells v1 is quite feature-freeze, we don't want
+        # to pass down request_spec to the manager and rather keep the
+        # cell conductor providing a new RequestSpec like the original
+        # behaviour
         cctxt = self.client.prepare(version='1.20')
         cctxt.cast(ctxt, 'live_migrate_instance',
                    instance=instance,
@@ -620,7 +625,12 @@ class CellsAPI(object):
     def rebuild_instance(self, ctxt, instance, new_pass, injected_files,
                          image_ref, orig_image_ref, orig_sys_metadata, bdms,
                          recreate=False, on_shared_storage=False, host=None,
-                         preserve_ephemeral=False, kwargs=None):
+                         preserve_ephemeral=False, request_spec=None,
+                         kwargs=None):
+        # NOTE(sbauza): Since Cells v1 is quite feature-freeze, we don't want
+        # to pass down request_spec to the manager and rather keep the
+        # cell conductor providing a new RequestSpec like the original
+        # behaviour
         cctxt = self.client.prepare(version='1.25')
         cctxt.cast(ctxt, 'rebuild_instance',
                    instance=instance, image_href=image_ref,

nova/tests/unit/cells/test_cells_rpcapi.py

@@ -682,6 +682,48 @@ class CellsAPITestCase(test.NoDBTestCase):
         self._check_result(call_info, 'live_migrate_instance',
                            expected_args, version='1.20')
 
+    def test_live_migrate_instance_not_passing_request_spec(self):
+        call_info = self._stub_rpc_method('cast', None)
+
+        self.cells_rpcapi.live_migrate_instance(self.fake_context,
+                                                'fake-instance',
+                                                'fake-host',
+                                                'fake-block',
+                                                'fake-commit',
+                                                'fake-spec')
+        expected_args = {'instance': 'fake-instance',
+                         'block_migration': 'fake-block',
+                         'disk_over_commit': 'fake-commit',
+                         'host_name': 'fake-host'}
+        self._check_result(call_info, 'live_migrate_instance',
+                           expected_args, version='1.20')
+
+    def test_rebuild_instance_not_passing_request_spec(self):
+        call_info = self._stub_rpc_method('cast', None)
+
+        self.cells_rpcapi.rebuild_instance(self.fake_context,
+                                           'fake-instance',
+                                           'fake-pass',
+                                           'fake-files',
+                                           'fake-image_ref',
+                                           'fake-orig_image_ref',
+                                           'fake-orig_sys_metadata',
+                                           'fake-bdms',
+                                           recreate=False,
+                                           on_shared_storage=False,
+                                           host=None,
+                                           preserve_ephemeral=False,
+                                           request_spec='fake-spec',
+                                           kwargs=None)
+        expected_args = {'instance': 'fake-instance',
+                         'image_href': 'fake-image_ref',
+                         'admin_password': 'fake-pass',
+                         'files_to_inject': 'fake-files',
+                         'preserve_ephemeral': False,
+                         'kwargs': None}
+        self._check_result(call_info, 'rebuild_instance',
+                           expected_args, version='1.25')
+
     def test_revert_resize(self):
         call_info = self._stub_rpc_method('cast', None)