oslo.messaging/tests/rpc/test_dispatcher.py

# 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.

import mock
import testscenarios

from oslo import messaging
from oslo.messaging import serializer as msg_serializer
from tests import utils as test_utils

load_tests = testscenarios.load_tests_apply_scenarios


class _FakeEndpoint(object):

    def __init__(self, target=None):
        self.target = target

    def foo(self, ctxt, **kwargs):
        pass

    def bar(self, ctxt, **kwargs):
        pass


class TestDispatcher(test_utils.BaseTestCase):

    scenarios = [
        ('no_endpoints',
         dict(endpoints=[],
              dispatch_to=None,
              ctxt={}, msg=dict(method='foo'),
              success=False, ex=messaging.UnsupportedVersion)),
        ('default_target',
         dict(endpoints=[{}],
              dispatch_to=dict(endpoint=0, method='foo'),
              ctxt={}, msg=dict(method='foo'),
              success=True, ex=None)),
        ('default_target_ctxt_and_args',
         dict(endpoints=[{}],
              dispatch_to=dict(endpoint=0, method='bar'),
              ctxt=dict(user='bob'), msg=dict(method='bar',
                                              args=dict(blaa=True)),
              success=True, ex=None)),
        ('default_target_namespace',
         dict(endpoints=[{}],
              dispatch_to=dict(endpoint=0, method='foo'),
              ctxt={}, msg=dict(method='foo', namespace=None),
              success=True, ex=None)),
        ('default_target_version',
         dict(endpoints=[{}],
              dispatch_to=dict(endpoint=0, method='foo'),
              ctxt={}, msg=dict(method='foo', version='1.0'),
              success=True, ex=None)),
        ('default_target_no_such_method',
         dict(endpoints=[{}],
              dispatch_to=None,
              ctxt={}, msg=dict(method='foobar'),
              success=False, ex=messaging.NoSuchMethod)),
        ('namespace',
         dict(endpoints=[{}, dict(namespace='testns')],
              dispatch_to=dict(endpoint=1, method='foo'),
              ctxt={}, msg=dict(method='foo', namespace='testns'),
              success=True, ex=None)),
        ('namespace_mismatch',
         dict(endpoints=[{}, dict(namespace='testns')],
              dispatch_to=None,
              ctxt={}, msg=dict(method='foo', namespace='nstest'),
              success=False, ex=messaging.UnsupportedVersion)),
        ('version',
         dict(endpoints=[dict(version='1.5'), dict(version='3.4')],
              dispatch_to=dict(endpoint=1, method='foo'),
              ctxt={}, msg=dict(method='foo', version='3.2'),
              success=True, ex=None)),
        ('version_mismatch',
         dict(endpoints=[dict(version='1.5'), dict(version='3.0')],
              dispatch_to=None,
              ctxt={}, msg=dict(method='foo', version='3.2'),
              success=False, ex=messaging.UnsupportedVersion)),
    ]

    def test_dispatcher(self):
        endpoints = [mock.Mock(spec=_FakeEndpoint,
                               target=messaging.Target(**e))
                     for e in self.endpoints]

        serializer = None
        target = messaging.Target()
        dispatcher = messaging.RPCDispatcher(target, endpoints, serializer)

        def check_reply(reply=None, failure=None, log_failure=True):
            if self.ex and failure is not None:
                ex = failure[1]
                self.assertFalse(self.success, ex)
                self.assertIsNotNone(self.ex, ex)
                self.assertIsInstance(ex, self.ex, ex)
                if isinstance(ex, messaging.NoSuchMethod):
                    self.assertEqual(self.msg.get('method'), ex.method)
                elif isinstance(ex, messaging.UnsupportedVersion):
                    self.assertEqual(self.msg.get('version', '1.0'),
                                     ex.version)
            else:
                self.assertTrue(self.success, failure)
                self.assertIsNone(failure)

        incoming = mock.Mock(ctxt=self.ctxt, message=self.msg)
        incoming.reply.side_effect = check_reply

        with dispatcher(incoming) as callback:
            callback()

        for n, endpoint in enumerate(endpoints):
            for method_name in ['foo', 'bar']:
                method = getattr(endpoint, method_name)
                if self.dispatch_to and n == self.dispatch_to['endpoint'] and \
                        method_name == self.dispatch_to['method']:
                    method.assert_called_once_with(
                        self.ctxt, **self.msg.get('args', {}))
                else:
                    self.assertEqual(0, method.call_count)

        self.assertEqual(1, incoming.reply.call_count)


class TestSerializer(test_utils.BaseTestCase):

    scenarios = [
        ('no_args_or_retval',
         dict(ctxt={}, dctxt={}, args={}, retval=None)),
        ('args_and_retval',
         dict(ctxt=dict(user='bob'),
              dctxt=dict(user='alice'),
              args=dict(a='a', b='b', c='c'),
              retval='d')),
    ]

    def test_serializer(self):
        endpoint = _FakeEndpoint()
        serializer = msg_serializer.NoOpSerializer()
        target = messaging.Target()
        dispatcher = messaging.RPCDispatcher(target, [endpoint], serializer)

        self.mox.StubOutWithMock(endpoint, 'foo')
        args = dict([(k, 'd' + v) for k, v in self.args.items()])
        endpoint.foo(self.dctxt, **args).AndReturn(self.retval)

        self.mox.StubOutWithMock(serializer, 'serialize_entity')
        self.mox.StubOutWithMock(serializer, 'deserialize_entity')
        self.mox.StubOutWithMock(serializer, 'deserialize_context')

        serializer.deserialize_context(self.ctxt).AndReturn(self.dctxt)

        for arg in self.args:
            serializer.deserialize_entity(self.dctxt, arg).AndReturn('d' + arg)

        serializer.serialize_entity(self.dctxt, self.retval).\
            AndReturn('s' + self.retval if self.retval else None)

        self.mox.ReplayAll()

        retval = dispatcher._dispatch(self.ctxt, dict(method='foo',
                                                      args=self.args))
        if self.retval is not None:
            self.assertEqual('s' + self.retval, retval)