Creating oslo.config.opts entry_points for plugins

To assist with automated configuration validation, we need entry points
for oslo.config.opts for each one of the plugins.

Change-Id: I7fc132f917949d147dd6371d54e01a6cfd995aae

os_vif/opts.py

@@ -0,0 +1,34 @@
+# Copyright (c) 2021 OpenStack Foundation.
+#
+# 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_plugins_opts',
+]
+
+from copy import deepcopy
+import os_vif
+
+
+os_vif.initialize()
+
+_EXT_MANAGER = os_vif._EXT_MANAGER
+
+plugins_list = [
+    (name, _EXT_MANAGER[name].obj)
+    for name in sorted(_EXT_MANAGER.names())
+]
+
+
+def list_plugins_opts():
+    return [('os_vif_' + g, deepcopy(o.CONFIG_OPTS)) for g, o in plugins_list]

os_vif/tests/unit/test_os_vif.py

@@ -18,6 +18,7 @@ from stevedore import extension
 import os_vif
 from os_vif import exception
 from os_vif import objects
+from os_vif import opts
 from os_vif import plugin
 from os_vif.tests.unit import base
 
@@ -170,3 +171,10 @@ class TestOSVIF(base.TestCase):
         vif_info = info.plugin_info[0].vif_info
         self.assertEqual(len(vif_info), 1)
         self.assertEqual(vif_info[0].vif_object_name, "VIFOpenVSwitch")
+
+    def test_list_opts_entrypoints(self):
+        list_opts = opts.list_plugins_opts()
+        for group in list_opts:
+            for opt in group[1]:
+                self.assertTrue("oslo_config.cfg" == opt.__module__)
+        self.assertGreaterEqual(len(list_opts), 3)

releasenotes/notes/oslo-config-opts-entrypoints-e83f907b686d774a.yaml

@@ -0,0 +1,6 @@
+---
+features:
+  - |
+    We now create entrypoints for oslo.config options to allow automated
+    documentation and validation of the configurable options for all the
+    plugins.

setup.cfg

@@ -31,3 +31,5 @@ os_vif =
     linux_bridge = vif_plug_linux_bridge.linux_bridge:LinuxBridgePlugin
     ovs = vif_plug_ovs.ovs:OvsPlugin
     noop = vif_plug_noop.noop:NoOpPlugin
+oslo.config.opts =
+    os_vif = os_vif.opts:list_plugins_opts