fix: load cache error when CacheDecoder object is not callable

dynamic/discovery.py

@@ -15,8 +15,10 @@
 import os
 import six
 import json
+import logging
 import hashlib
 import tempfile
+from functools import partial
 from collections import defaultdict
 from abc import abstractmethod, abstractproperty
 
@@ -54,11 +56,12 @@ def __init_cache(self, refresh=False):
         else:
             try:
                 with open(self.__cache_file, 'r') as f:
-                    self._cache = json.load(f, cls=CacheDecoder(self.client))
+                    self._cache = json.load(f, cls=partial(CacheDecoder, self.client))
                 if self._cache.get('library_version') != __version__:
                     # Version mismatch, need to refresh cache
                     self.invalidate_cache()
-            except Exception:
+            except Exception as e:
+                logging.error("load cache error: %s", e)
                 self.invalidate_cache()
         self._load_server_info()
         self.discover()

dynamic/test_discovery.py

@@ -0,0 +1,40 @@
+# Copyright 2019 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 os
+import unittest
+
+from kubernetes.e2e_test import base
+from kubernetes.client import api_client
+
+from . import DynamicClient
+
+
+class TestDiscoverer(unittest.TestCase):
+
+    @classmethod
+    def setUpClass(cls):
+        cls.config = base.get_e2e_configuration()
+
+    def test_init_cache_from_file(self):
+        client = DynamicClient(api_client.ApiClient(configuration=self.config))
+        client.resources.get(api_version='v1', kind='Node')
+        mtime1 = os.path.getmtime(client.resources._Discoverer__cache_file)
+
+        client = DynamicClient(api_client.ApiClient(configuration=self.config))
+        client.resources.get(api_version='v1', kind='Node')
+        mtime2 = os.path.getmtime(client.resources._Discoverer__cache_file)
+
+        # test no Discoverer._write_cache called
+        self.assertTrue(mtime1 == mtime2)