use stevedore to load extensions

pkg_resources was deprecated in python3.12

Change-Id: Ifa4c93220d3f39f706cc7fd462f28ebcdce14707

Author: wchy1001

requirements.txt

@@ -11,3 +11,4 @@ python-swiftclient>=3.2.0 # Apache-2.0
 python-mistralclient!=3.2.0,>=3.1.0 # Apache-2.0
 osc-lib>=1.8.0 # Apache-2.0
 python-openstackclient>=3.12.0 # Apache-2.0
+stevedore>=2.0.1 # Apache-2.0

troveclient/auth_plugin.py

@@ -17,7 +17,7 @@
 
 import logging
 
-import pkg_resources
+import stevedore
 
 from troveclient import exceptions
 
@@ -33,15 +33,12 @@ def discover_auth_systems():
 
     This won't take into account the old style auth-systems.
     """
-    ep_name = 'openstack.client.auth_plugin'
-    for ep in pkg_resources.iter_entry_points(ep_name):
-        try:
-            auth_plugin = ep.load()
-        except (ImportError, pkg_resources.UnknownExtra, AttributeError) as e:
-            LOG.debug("ERROR: Cannot load auth plugin %s", ep.name)
-            LOG.debug(e, exc_info=1)
-        else:
-            _discovered_plugins[ep.name] = auth_plugin
+    global _discovered_plugins
+    mgr = stevedore.ExtensionManager(
+        namespace='openstack.client.auth_plugin',
+        invoke_on_load=True,
+    )
+    _discovered_plugins = {ext.name: ext.obj for ext in mgr}
 
 
 def load_auth_system_opts(parser):
@@ -60,7 +57,7 @@ def load_auth_system_opts(parser):
 
 def load_plugin(auth_system):
     if auth_system in _discovered_plugins:
-        return _discovered_plugins[auth_system]()
+        return _discovered_plugins[auth_system]
 
     raise exceptions.AuthSystemNotFound(auth_system)
 

troveclient/shell.py

@@ -33,7 +33,8 @@
 from keystoneauth1 import loading
 from oslo_utils import encodeutils
 from oslo_utils import importutils
-import pkg_resources
+import stevedore
+
 
 from troveclient.apiclient import exceptions as exc
 import troveclient.auth_plugin
@@ -323,11 +324,10 @@ def _discover_via_contrib_path(self, version):
             yield name, module
 
     def _discover_via_entry_points(self):
-        for ep in pkg_resources.iter_entry_points('troveclient.extension'):
-            name = ep.name
-            module = ep.load()
-
-            yield name, module
+        mgr = stevedore.ExtensionManager(namespace='troveclient.extension',
+                                         invoke_on_load=True)
+        for ext in mgr:
+            yield ext.name, ext.plugin
 
     def _add_bash_completion_subparser(self, subparsers):
         subparser = subparsers.add_parser(

troveclient/tests/test_discover.py

@@ -17,34 +17,13 @@
 import types
 from unittest import mock
 
-import pkg_resources
 import testtools
 
 import troveclient.shell
 
 
 class DiscoverTest(testtools.TestCase):
 
-    def test_discover_via_entry_points(self):
-
-        def mock_iter_entry_points(group):
-            if group == 'troveclient.extension':
-                fake_ep = mock.Mock()
-                fake_ep.name = 'foo'
-                fake_ep.module = types.ModuleType('foo')
-                fake_ep.load.return_value = fake_ep.module
-                return [fake_ep]
-
-        @mock.patch.object(pkg_resources, 'iter_entry_points',
-                           mock_iter_entry_points)
-        def test():
-            shell = troveclient.shell.OpenStackTroveShell()
-            for name, module in shell._discover_via_entry_points():
-                self.assertEqual('foo', name)
-                self.assertTrue(inspect.ismodule(module))
-
-        test()
-
     def test_discover_extensions(self):
 
         def mock_discover_via_python_path(self):