Correct use of ConfigFilesNotFoundError

ConfigFilesNotFoundError.__init__() takes "config_files", not
"path". And pass the config value itself rather than the result
of find_file(), which is always None.

Change-Id: Ia5285d252d5636892c4fbeb9191a6c7ed4923b78
Closes-Bug: 1236176
(cherry picked from commit 84b02ca1d5)

nova/cells/state.py

@@ -151,7 +151,7 @@ class CellStateManager(base.Base):
         if cells_config:
             config_path = CONF.find_file(cells_config)
             if not config_path:
-                raise cfg.ConfigFilesNotFoundError(path=config_path)
+                raise cfg.ConfigFilesNotFoundError(config_files=[cells_config])
             return CellStateManagerFile(cell_state_cls, config_path)
 
         return CellStateManagerDB(cell_state_cls)

nova/tests/cells/test_cells_state_manager.py

@@ -16,6 +16,8 @@
 Tests For CellStateManager
 """
 
+from oslo.config import cfg
+
 from nova.cells import state
 from nova import db
 from nova.db.sqlalchemy import models
@@ -65,6 +67,12 @@ class TestCellsStateManager(test.TestCase):
         self.stubs.Set(db, 'compute_node_get_all', _fake_compute_node_get_all)
         self.stubs.Set(db, 'flavor_get_all', _fake_instance_type_all)
 
+    def test_cells_config_not_found(self):
+        self.flags(cells_config='no_such_file_exists.conf', group='cells')
+        e = self.assertRaises(cfg.ConfigFilesNotFoundError,
+                              state.CellStateManager)
+        self.assertEqual(['no_such_file_exists.conf'], e.config_files)
+
     def test_capacity_no_reserve(self):
         # utilize entire cell
         cap = self._capacity(0.0)