Restore submodule access through the deprecated kubernetes.client.apis package

kubernetes/client/apis/__init__.py

@@ -1,4 +1,6 @@
 from __future__ import absolute_import
+from importlib import import_module as _import_module
+from types import ModuleType as _ModuleType
 import warnings
 
 # flake8: noqa
@@ -11,3 +13,18 @@
     "The package kubernetes.client.apis is renamed and deprecated, use kubernetes.client.api instead (please note that the trailing s was removed).",
     DeprecationWarning
 )
+
+
+def __getattr__(name: str) -> _ModuleType:
+    # kubernetes.client.api imports its submodules lazily, so the star import
+    # above no longer brings in module names such as core_v1_api.
+    if name.startswith('_') or not name.isidentifier():
+        raise AttributeError(f"module {__name__!r} has no attribute {name!r}")
+    module_name = f"kubernetes.client.api.{name}"
+    try:
+        return _import_module(module_name)
+    except ModuleNotFoundError as e:
+        if e.name != module_name:
+            raise
+        raise AttributeError(
+            f"module {__name__!r} has no attribute {name!r}") from None

kubernetes/test/test_apis_alias.py

@@ -0,0 +1,81 @@
+# Copyright 2026 The Kubernetes Authors.
+#
+# 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 importlib
+import pkgutil
+import unittest
+from unittest import mock
+import warnings
+
+import kubernetes.client.api
+
+
+def _import_alias():
+    # The alias installs its own 'default' filter for its DeprecationWarning,
+    # so record the warning instead of trying to filter it out.
+    with warnings.catch_warnings(record=True):
+        return importlib.import_module('kubernetes.client.apis')
+
+
+class TestApisAlias(unittest.TestCase):
+    @classmethod
+    def setUpClass(cls):
+        cls.apis = _import_alias()
+
+    def test_from_import_submodule(self):
+        from kubernetes.client.apis import core_v1_api
+
+        self.assertIs(
+            core_v1_api,
+            importlib.import_module('kubernetes.client.api.core_v1_api'))
+
+    def test_every_api_submodule_is_reachable(self):
+        names = [m.name for m in pkgutil.iter_modules(
+            kubernetes.client.api.__path__)]
+        self.assertIn('core_v1_api', names)
+        for name in names:
+            with self.subTest(name=name):
+                self.assertIs(
+                    getattr(self.apis, name),
+                    importlib.import_module('kubernetes.client.api.' + name))
+
+    def test_from_import_class(self):
+        from kubernetes.client.apis import CoreV1Api
+
+        self.assertIs(CoreV1Api, kubernetes.client.api.CoreV1Api)
+
+    def test_unknown_name(self):
+        with self.assertRaises(ImportError):
+            from kubernetes.client.apis import no_such_api  # noqa: F401
+        self.assertFalse(hasattr(self.apis, 'no_such_api'))
+
+    def test_non_submodule_names_are_not_imported(self):
+        with mock.patch('kubernetes.client.apis._import_module') as m:
+            for name in ('__wrapped__', '_no_such_api', '.core_v1_api'):
+                with self.subTest(name=name):
+                    self.assertFalse(hasattr(self.apis, name))
+        m.assert_not_called()
+
+    def test_missing_dependency_propagates(self):
+        error = ModuleNotFoundError("No module named 'missing_dep'",
+                                    name='missing_dep')
+        with mock.patch('kubernetes.client.apis._import_module',
+                        side_effect=error):
+            with self.assertRaises(ModuleNotFoundError) as cm:
+                self.apis.core_v1_api
+        self.assertIs(cm.exception, error)
+
+
+if __name__ == '__main__':
+    unittest.main()