Fix compatability with new oslo.messaging

A recent change to oslo.messaging to redact contexts before sending them
to a notification bus broke masakari due to the invalid default for
read_deleted. This ensures that a "None" value for read_deleted ends up
being interpreted as a 'none'.

Related-bug: #2030976
Change-Id: Ic9b895601f301c1e9ba135766493d4234fa9b50b

masakari/context.py

@@ -117,7 +117,12 @@ class RequestContext(context.RequestContext):
             LOG.debug('Arguments dropped when creating context: %s',
                       str(kwargs))
 
-        self.read_deleted = read_deleted
+        if read_deleted is None:
+            # If we did not get a value for read_deleted, ensure we default
+            # it to "no" as code expects it to be a string.
+            self.read_deleted = 'no'
+        else:
+            self.read_deleted = read_deleted
         self.remote_address = remote_address
         if not timestamp:
             timestamp = timeutils.utcnow()

masakari/tests/unit/test_context.py

@@ -57,6 +57,11 @@ class ContextTestCase(test.NoDBTestCase):
         ctxt.read_deleted = 'no'
         self.assertEqual('no', ctxt.read_deleted)
 
+    def test_request_context_read_deleted_none(self):
+        ctxt = context.RequestContext('111',
+                                    '222')
+        self.assertEqual('no', ctxt.read_deleted)
+
     def test_request_context_read_deleted_invalid(self):
         self.assertRaises(ValueError,
                           context.RequestContext,