diff --git a/doc/source/server.rst b/doc/source/server.rst
index 64b19b828..933829f3a 100644
--- a/doc/source/server.rst
+++ b/doc/source/server.rst
@@ -12,3 +12,7 @@ Server
.. autoclass:: MessageHandlingServer
:members:
+
+.. autofunction:: expected_exceptions
+
+.. autoexception:: ExpectedException
diff --git a/oslo/messaging/_drivers/amqpdriver.py b/oslo/messaging/_drivers/amqpdriver.py
index ab77f4f78..3486a53a6 100644
--- a/oslo/messaging/_drivers/amqpdriver.py
+++ b/oslo/messaging/_drivers/amqpdriver.py
@@ -37,7 +37,8 @@ class AMQPIncomingMessage(base.IncomingMessage):
self.msg_id = msg_id
self.reply_q = reply_q
- def _send_reply(self, conn, reply=None, failure=None, ending=False):
+ def _send_reply(self, conn, reply=None, failure=None,
+ ending=False, log_failure=True):
if failure:
failure = rpc_common.serialize_remote_exception(failure)
@@ -56,9 +57,9 @@ class AMQPIncomingMessage(base.IncomingMessage):
else:
conn.direct_send(self.msg_id, rpc_common.serialize_msg(msg))
- def reply(self, reply=None, failure=None):
+ def reply(self, reply=None, failure=None, log_failure=True):
with self.listener.driver._get_connection() as conn:
- self._send_reply(conn, reply, failure)
+ self._send_reply(conn, reply, failure, log_failure=log_failure)
self._send_reply(conn, ending=True)
diff --git a/oslo/messaging/_drivers/base.py b/oslo/messaging/_drivers/base.py
index 1dd49f4e6..0868d6d1d 100644
--- a/oslo/messaging/_drivers/base.py
+++ b/oslo/messaging/_drivers/base.py
@@ -33,7 +33,7 @@ class IncomingMessage(object):
self.message = message
@abc.abstractmethod
- def reply(self, reply=None, failure=None):
+ def reply(self, reply=None, failure=None, log_failure=True):
"Send a reply or failure back to the client."
diff --git a/oslo/messaging/_drivers/impl_fake.py b/oslo/messaging/_drivers/impl_fake.py
index 3b4c99e18..7b9ab6d57 100644
--- a/oslo/messaging/_drivers/impl_fake.py
+++ b/oslo/messaging/_drivers/impl_fake.py
@@ -31,7 +31,7 @@ class FakeIncomingMessage(base.IncomingMessage):
super(FakeIncomingMessage, self).__init__(listener, ctxt, message)
self._reply_q = reply_q
- def reply(self, reply=None, failure=None):
+ def reply(self, reply=None, failure=None, log_failure=True):
# FIXME: handle failure
if self._reply_q:
self._reply_q.put(reply)
diff --git a/oslo/messaging/_executors/base.py b/oslo/messaging/_executors/base.py
index 62101a759..7a58bb4f4 100644
--- a/oslo/messaging/_executors/base.py
+++ b/oslo/messaging/_executors/base.py
@@ -16,6 +16,8 @@ import abc
import logging
import sys
+from oslo import messaging
+
_LOG = logging.getLogger(__name__)
@@ -33,6 +35,10 @@ class ExecutorBase(object):
reply = self.callback(incoming.ctxt, incoming.message)
if reply:
incoming.reply(reply)
+ except messaging.ExpectedException as e:
+ _LOG.debug('Expected exception during message handling (%s)' %
+ e.exc_info[1])
+ incoming.reply(failure=e.exc_info, log_failure=False)
except Exception:
# sys.exc_info() is deleted by LOG.exception().
exc_info = sys.exc_info()
diff --git a/oslo/messaging/rpc/__init__.py b/oslo/messaging/rpc/__init__.py
index c69e4b083..69d0ebd87 100644
--- a/oslo/messaging/rpc/__init__.py
+++ b/oslo/messaging/rpc/__init__.py
@@ -15,12 +15,14 @@
__all__ = [
'ClientSendError',
+ 'ExpectedException',
'NoSuchMethod',
'RPCClient',
'RPCDispatcher',
'RPCDispatcherError',
'RPCVersionCapError',
'UnsupportedVersion',
+ 'expected_exceptions',
'get_rpc_server',
]
diff --git a/oslo/messaging/rpc/server.py b/oslo/messaging/rpc/server.py
index 943400e43..8c86ce448 100644
--- a/oslo/messaging/rpc/server.py
+++ b/oslo/messaging/rpc/server.py
@@ -89,7 +89,13 @@ return values from the methods. By supplying a serializer object, a server can
deserialize arguments from - serialize return values to - primitive types.
"""
-__all__ = ['get_rpc_server']
+__all__ = [
+ 'get_rpc_server',
+ 'ExpectedException',
+ 'expected_exceptions',
+]
+
+import sys
from oslo.messaging.rpc import dispatcher as rpc_dispatcher
from oslo.messaging import server as msg_server
@@ -117,3 +123,38 @@ def get_rpc_server(transport, target, endpoints,
dispatcher = rpc_dispatcher.RPCDispatcher(endpoints, serializer)
return msg_server.MessageHandlingServer(transport, target,
dispatcher, executor)
+
+
+class ExpectedException(Exception):
+ """Encapsulates an expected exception raised by an RPC endpoint
+
+ Merely instantiating this exception records the current exception
+ information, which will be passed back to the RPC client without
+ exceptional logging.
+ """
+ def __init__(self):
+ self.exc_info = sys.exc_info()
+
+
+def expected_exceptions(*exceptions):
+ """Decorator for RPC endpoint methods that raise expected exceptions.
+
+ Marking an endpoint method with this decorator allows the declaration
+ of expected exceptions that the RPC server should not consider fatal,
+ and not log as if they were generated in a real error scenario.
+
+ Note that this will cause listed exceptions to be wrapped in an
+ ExpectedException, which is used internally by the RPC sever. The RPC
+ client will see the original exception type.
+ """
+ def outer(func):
+ def inner(*args, **kwargs):
+ try:
+ return func(*args, **kwargs)
+ except Exception as e:
+ if type(e) in exceptions:
+ raise ExpectedException()
+ else:
+ raise
+ return inner
+ return outer
diff --git a/tests/test_expected_exceptions.py b/tests/test_expected_exceptions.py
new file mode 100644
index 000000000..1585e4b0d
--- /dev/null
+++ b/tests/test_expected_exceptions.py
@@ -0,0 +1,54 @@
+
+# Copyright 2012 OpenStack Foundation
+# Copyright 2013 Red Hat, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+from oslo import messaging
+
+from tests import utils as test_utils
+
+
+class TestExpectedExceptions(test_utils.BaseTestCase):
+
+ def test_exception(self):
+ e = None
+ try:
+ try:
+ raise ValueError()
+ except Exception:
+ raise messaging.ExpectedException()
+ except messaging.ExpectedException as e:
+ self.assertIsInstance(e, messaging.ExpectedException)
+ self.assertTrue(hasattr(e, 'exc_info'))
+ self.assertIsInstance(e.exc_info[1], ValueError)
+
+ def test_decorator_expected(self):
+ class FooException(Exception):
+ pass
+
+ @messaging.expected_exceptions(FooException)
+ def naughty():
+ raise FooException()
+
+ self.assertRaises(messaging.ExpectedException, naughty)
+
+ def test_decorator_unexpected(self):
+ class FooException(Exception):
+ pass
+
+ @messaging.expected_exceptions(FooException)
+ def really_naughty():
+ raise ValueError()
+
+ self.assertRaises(ValueError, really_naughty)
diff --git a/tests/test_rabbit.py b/tests/test_rabbit.py
index 4f845b8be..31c03f566 100644
--- a/tests/test_rabbit.py
+++ b/tests/test_rabbit.py
@@ -60,7 +60,8 @@ class TestSendReceive(test_utils.BaseTestCase):
_failure = [
('success', dict(failure=False)),
- ('failure', dict(failure=True)),
+ ('failure', dict(failure=True, expected=False)),
+ ('expected_failure', dict(failure=True, expected=True)),
]
_timeout = [
@@ -134,7 +135,8 @@ class TestSendReceive(test_utils.BaseTestCase):
raise ZeroDivisionError
except Exception:
failure = sys.exc_info()
- msgs[i].reply(failure=failure)
+ msgs[i].reply(failure=failure,
+ log_failure=not self.expected)
else:
msgs[i].reply({'bar': msgs[i].message['foo']})
senders[i].join()