Merge "Fix fernet key writing for python 3"

keystone/token/providers/fernet/utils.py

@@ -99,7 +99,7 @@ def _create_new_key(keystone_user_id, keystone_group_id):
 
     Create a new key that is readable by the Keystone group and Keystone user.
     """
-    key = fernet.Fernet.generate_key()
+    key = fernet.Fernet.generate_key()  # key is bytes
 
     # This ensures the key created is not world-readable
     old_umask = os.umask(0o177)
@@ -117,7 +117,7 @@ def _create_new_key(keystone_user_id, keystone_group_id):
     key_file = os.path.join(CONF.fernet_tokens.key_repository, '0')
     try:
         with open(key_file, 'w') as f:
-            f.write(key)
+            f.write(key.decode('utf-8'))  # convert key to str for the file.
     finally:
         # After writing the key, set the umask back to it's original value. Do
         # the same with group and user identifiers if a Keystone group or user