Init zun centralize config

Initialize zun centralize config folder and test cases.

Change-Id: I93b0186c431947fe54650dd5d030e659d6776f41
Implements:blueprint centralize-config-zun

etc/zun/zun-config-generator.conf

@@ -0,0 +1,5 @@
+[DEFAULT]
+output_file = etc/zun/zun.conf.sample
+wrap_width = 79
+
+namespace=zun.conf

setup.cfg

@@ -52,6 +52,7 @@ console_scripts =
 
 oslo.config.opts =
     zun = zun.opts:list_opts
+    zun.conf = zun.opts:list_opts
 
 oslo.config.opts.defaults =
     zun = zun.common.config:set_cors_middleware_defaults

zun/conf/__init__.py

@@ -0,0 +1,31 @@
+# All Rights Reserved.
+#
+#    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_config import cfg
+
+# from zun.conf import api
+# from zun.conf import compute
+# from zun.conf import database
+# from zun.conf import glance_client
+# from zun.conf import keystone
+# from zun.conf import zun_client
+
+CONF = cfg.CONF
+
+# api.register_opts(CONF)
+# compute.register_opts(CONF)
+# database.register_opts(CONF)
+# glance_client.register_opts(CONF)
+# keystone.register_opts(CONF)
+# zun_client.register_opts(CONF)

zun/conf/opts.py

@@ -0,0 +1,79 @@
+# Copyright 2015 OpenStack Foundation
+# All Rights Reserved.
+#
+#    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.
+
+"""
+This is the single point of entry to generate the sample configuration
+file for Zun. It collects all the necessary info from the other modules
+in this package. It is assumed that:
+
+* every other module in this package has a 'list_opts' function which
+  return a dict where
+  * the keys are strings which are the group names
+  * the value of each key is a list of config options for that group
+* the zun.conf package doesn't have further packages with config options
+* this module is only used in the context of sample file generation
+"""
+
+import collections
+import importlib
+import os
+import pkgutil
+
+LIST_OPTS_FUNC_NAME = "list_opts"
+
+
+def _tupleize(dct):
+    """Take the dict of options and convert to the 2-tuple format."""
+    return [(key, val) for key, val in dct.items()]
+
+
+def list_opts():
+    opts = collections.defaultdict(list)
+    module_names = _list_module_names()
+    imported_modules = _import_modules(module_names)
+    _append_config_options(imported_modules, opts)
+    return _tupleize(opts)
+
+
+def _list_module_names():
+    module_names = []
+    package_path = os.path.dirname(os.path.abspath(__file__))
+    for _, modname, ispkg in pkgutil.iter_modules(path=[package_path]):
+        if modname == "opts" or ispkg:
+            continue
+        else:
+            module_names.append(modname)
+    return module_names
+
+
+def _import_modules(module_names):
+    imported_modules = []
+    for modname in module_names:
+        mod = importlib.import_module("zun.conf." + modname)
+        if not hasattr(mod, LIST_OPTS_FUNC_NAME):
+            msg = "The module 'zun.conf.%s' should have a '%s' "\
+                  "function which returns the config options." % \
+                  (modname, LIST_OPTS_FUNC_NAME)
+            raise AttributeError(msg)
+        else:
+            imported_modules.append(mod)
+    return imported_modules
+
+
+def _append_config_options(imported_modules, config_options):
+    for mod in imported_modules:
+        configs = mod.list_opts()
+        for key, val in configs.items():
+            config_options[key].extend(val)

zun/tests/unit/conf/test_conf.py

@@ -0,0 +1,64 @@
+# 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 collections
+import mock
+from oslo_config import cfg
+
+from zun.conf import opts
+from zun.tests import base
+
+
+class ConfTestCase(base.TestCase):
+
+    def test_list_opts(self):
+        for group, opt_list in opts.list_opts():
+            self.assertIsInstance(group, cfg.OptGroup)
+            for opt in opt_list:
+                self.assertIsInstance(opt, cfg.Opt)
+
+    def test_list_module_name_invalid_mods(self):
+        with mock.patch('pkgutil.iter_modules') as mock_mods:
+            mock_mods.return_value = [(None, 'foo', True),
+                                      (None, 'opts', False)]
+            self.assertEqual([], opts._list_module_names())
+
+    def test_list_module_name_valid_mods(self):
+        with mock.patch('pkgutil.iter_modules') as mock_mods:
+            mock_mods.return_value = [(None, 'foo', False)]
+            self.assertEqual(['foo'], opts._list_module_names())
+
+    def test_import_mods_no_func(self):
+        modules = ['foo', 'bar']
+        with mock.patch('importlib.import_module') as mock_import:
+            mock_import.return_value = mock.sentinel.mods
+            self.assertRaises(AttributeError, opts._import_modules, modules)
+            mock_import.assert_called_once_with('zun.conf.foo')
+
+    def test_import_mods_valid_func(self):
+        modules = ['foo', 'bar']
+        with mock.patch('importlib.import_module') as mock_import:
+            mock_mod = mock.MagicMock()
+            mock_import.return_value = mock_mod
+            self.assertEqual([mock_mod, mock_mod],
+                             opts._import_modules(modules))
+            mock_import.assert_has_calls([mock.call('zun.conf.foo'),
+                                          mock.call('zun.conf.bar')])
+
+    def test_append_config(self):
+        opt = collections.defaultdict(list)
+        mock_module = mock.MagicMock()
+        mock_conf = mock.MagicMock()
+        mock_module.list_opts.return_value = mock_conf
+        mock_conf.items.return_value = [('foo', 'bar')]
+        opts._append_config_options([mock_module], opt)
+        self.assertEqual({'foo': ['b', 'a', 'r']}, opt)