Add kwargs to RequestContext __init__

Fixes bug 949726

This allows processing of rpc messages that contain older versions of
RequestContext to not raise an exception.

Change-Id: I4891a44280fcb8accf0cef1c00c1123029abcc96

nova/context.py

@@ -22,9 +22,13 @@
 import copy
 
 from nova import local
+from nova import log as logging
 from nova import utils
 
 
+LOG = logging.getLogger(__name__)
+
+
 def generate_request_id():
     return 'req-' + str(utils.gen_uuid())
 
@@ -38,7 +42,7 @@ class RequestContext(object):
 
     def __init__(self, user_id, project_id, is_admin=None, read_deleted="no",
                  roles=None, remote_address=None, timestamp=None,
-                 request_id=None, auth_token=None, overwrite=True):
+                 request_id=None, auth_token=None, overwrite=True, **kwargs):
         """
         :param read_deleted: 'no' indicates deleted records are hidden, 'yes'
             indicates deleted records are visible, 'only' indicates that
@@ -46,10 +50,16 @@ class RequestContext(object):
 
         :param overwrite: Set to False to ensure that the greenthread local
             copy of the index is not overwritten.
+
+        :param kwargs: Extra arguments that might be present, but we ignore
+            because they possibly came in from older rpc messages.
         """
         if read_deleted not in ('no', 'yes', 'only'):
             raise ValueError(_("read_deleted can only be one of 'no', "
                                "'yes' or 'only', not %r") % read_deleted)
+        if kwargs:
+            LOG.warn(_('Arguments dropped when creating context: %s') %
+                    str(kwargs))
 
         self.user_id = user_id
         self.project_id = project_id

nova/tests/test_context.py

@@ -44,3 +44,17 @@ class ContextTestCase(test.TestCase):
                           '111',
                           '222',
                           read_deleted=True)
+
+    def test_extra_args_to_context_get_logged(self):
+        info = {}
+
+        def fake_warn(log_msg):
+            info['log_msg'] = log_msg
+
+        self.stubs.Set(context.LOG, 'warn', fake_warn)
+
+        c = context.RequestContext('user', 'project',
+                extra_arg1='meow', extra_arg2='wuff')
+        self.assertTrue(c)
+        self.assertIn("'extra_arg1': 'meow'", info['log_msg'])
+        self.assertIn("'extra_arg2': 'wuff'", info['log_msg'])