Merge pull request #39852 from rallytime/bp-39651

Back-port #39651 to 2016.11

salt/cache/__init__.py

@@ -143,8 +143,8 @@ class Cache(object):
             added by the driver itself.
 
         :return:
-            Return a python object fetched from the cache or None if the given
-            path or key not found.
+            Return a python object fetched from the cache or an empty dict if
+            the given path or key not found.
 
         :raises SaltCacheError:
             Raises an exception if cache driver detected an error accessing data

salt/cache/consul.py

@@ -104,7 +104,7 @@ def fetch(bank, key):
     try:
         _, value = api.kv.get(c_key)
         if value is None:
-            return value
+            return {}
         return __context__['serial'].loads(value['Value'])
     except Exception as exc:
         raise SaltCacheError(

salt/cache/localfs.py

@@ -61,7 +61,7 @@ def fetch(bank, key, cachedir):
     key_file = os.path.join(cachedir, os.path.normpath(bank), '{0}.p'.format(key))
     if not os.path.isfile(key_file):
         log.debug('Cache file "%s" does not exist', key_file)
-        return None
+        return {}
     try:
         with salt.utils.fopen(key_file, 'rb') as fh_:
             return __context__['serial'].load(fh_)

salt/utils/master.py

@@ -134,6 +134,14 @@ class MasterPillarUtil(object):
             if not salt.utils.verify.valid_id(self.opts, minion_id):
                 continue
             mdata = self.cache.fetch('minions/{0}'.format(minion_id), 'data')
+            if not isinstance(mdata, dict):
+                log.warning(
+                    'cache.fetch should always return a dict. ReturnedType: {0}, MinionId: {1}'.format(
+                        type(mdata).__name__,
+                        minion_id
+                    )
+                )
+                continue
             if 'grains' in mdata:
                 grains[minion_id] = mdata['grains']
             if 'pillar' in mdata:

tests/unit/cache/localfs_test.py

@@ -100,10 +100,10 @@ class LocalFSTest(TestCase):
     @patch('os.path.isfile', MagicMock(return_value=False))
     def test_fetch_return_when_cache_file_does_not_exist(self):
         '''
-        Tests that the fetch function returns None when the cache key file doesn't
-        exist.
+        Tests that the fetch function returns an empty dic when the cache key file
+        doesn't exist.
         '''
-        self.assertIsNone(localfs.fetch(bank='', key='', cachedir=''))
+        self.assertEqual(localfs.fetch(bank='', key='', cachedir=''), {})
 
     @patch('os.path.isfile', MagicMock(return_value=True))
     @patch('salt.utils.fopen', MagicMock(side_effect=IOError))