Merge "Expose an entry point to list all config options"

doc/source/index.rst

@@ -17,6 +17,7 @@ Contents
    notifier
    serializer
    exceptions
+   opts
    conffixture
 
 Release Notes

oslo/messaging/opts.py

@@ -0,0 +1,75 @@
+
+# Copyright 2014 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.
+
+__all__ = [
+    'list_opts'
+]
+
+import copy
+import itertools
+
+from oslo.messaging._drivers import amqp
+from oslo.messaging._drivers import common as drivers_common
+from oslo.messaging._drivers import impl_qpid
+from oslo.messaging._drivers import impl_rabbit
+from oslo.messaging._drivers import impl_zmq
+from oslo.messaging._drivers import matchmaker
+from oslo.messaging._drivers import matchmaker_redis
+from oslo.messaging._drivers import matchmaker_ring
+from oslo.messaging._executors import impl_eventlet
+from oslo.messaging.notify import notifier
+from oslo.messaging.rpc import client
+from oslo.messaging import transport
+
+_global_opt_lists = [
+    amqp.amqp_opts,
+    drivers_common._exception_opts,
+    impl_qpid.qpid_opts,
+    impl_rabbit.rabbit_opts,
+    impl_zmq.zmq_opts,
+    matchmaker.matchmaker_opts,
+    matchmaker_redis.matchmaker_redis_opts,
+    impl_eventlet._eventlet_opts,
+    notifier._notifier_opts,
+    client._client_opts,
+    transport._transport_opts
+]
+
+_opts = [
+    (None, list(itertools.chain(*_global_opt_lists))),
+    ('matchmaker_ring', matchmaker_ring.matchmaker_opts),
+]
+
+
+def list_opts():
+    """Return a list of oslo.config options available in the library.
+
+    The returned list includes all oslo.config options which may be registered
+    at runtime by the library.
+
+    Each element of the list is a tuple. The first element is the name of the
+    group under which the list of elements in the second element will be
+    registered. A group name of None corresponds to the [DEFAULT] group in
+    config files.
+
+    This function is also discoverable via the 'oslo.messaging' entry point
+    under the 'oslo.config.opts' namespace.
+
+    The purpose of this is to allow tools like the Oslo sample config file
+    generator to discover the options exposed to users by this library.
+
+    :returns: a list of (group_name, opts) tuples
+    """
+    return [(g, copy.deepcopy(o)) for g, o in _opts]

setup.cfg

@@ -50,6 +50,9 @@ oslo.messaging.notify.drivers =
     noop = oslo.messaging.notify._impl_noop:NoOpDriver
     routing = oslo.messaging.notify._impl_routing:RoutingDriver
 
+oslo.config.opts =
+    oslo.messaging = oslo.messaging.opts:list_opts
+
 [build_sphinx]
 source-dir = doc/source
 build-dir = doc/build

tests/test_opts.py

@@ -0,0 +1,47 @@
+
+# Copyright 2014 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 pkg_resources
+
+from oslo.messaging import opts
+from tests import utils as test_utils
+
+
+class OptsTestCase(test_utils.BaseTestCase):
+
+    def _test_list_opts(self, result):
+        self.assertEqual(2, len(result))
+
+        groups = [g for (g, l) in result]
+        self.assertIn(None, groups)
+        self.assertIn('matchmaker_ring', groups)
+
+        opt_names = [o.name for (g, l) in result for o in l]
+        self.assertIn('rpc_backend', opt_names)
+        self.assertIn('allowed_rpc_exception_modules', opt_names)
+
+    def test_list_opts(self):
+        self._test_list_opts(opts.list_opts())
+
+    def test_entry_point(self):
+        result = None
+        for ep in pkg_resources.iter_entry_points('oslo.config.opts'):
+            if ep.name == "oslo.messaging":
+                list_fn = ep.load()
+                result = list_fn()
+                break
+
+        self.assertIsNotNone(result)
+        self._test_list_opts(result)