Propagate name of system service account to the bot.

appengine/swarming/swarming_bot/bot_code/bot_auth_test.py

 #!/usr/bin/env python
 # Copyright 2016 The LUCI Authors. All rights reserved.
 # Use of this source code is governed under the Apache License, Version 2.0
 # that can be found in the LICENSE file.
 
 import json
 import logging
 import os
 import sys
 import tempfile
@@ skipping 39 matching lines @@
     with open(path, 'w') as f:
       json.dump(auth_params._asdict(), f)
     return path
 
   def test_bot_auth_works(self):
     # If 'task_service_account' is 'bot', local HTTP server returns bot tokens.
     exp = int(time.time() + 3600)
     auth_params_path = self.write_auth_params(bot_auth.AuthParams(
         swarming_http_headers={'Authorization': 'Bearer bot-own-token'},
         swarming_http_headers_exp=exp,
+        system_service_account='none',
         task_service_account='bot'))
     with bot_auth.AuthSystem(auth_params_path) as auth_sys:
       self.assertEqual(
           ({'Authorization': 'Bearer bot-own-token'}, exp),
           auth_sys.get_bot_headers())
       self.assertEqual(
           ['rpc_port', 'secret'],
           sorted(auth_sys.local_auth_context))
       # Try to actually use the local RPC service to grab a token.
       resp = call_rpc(auth_sys.local_auth_context, ['A', 'B', 'C'])
       self.assertEqual([u'access_token', u'expiry'], sorted(resp))
       self.assertEqual(u'bot-own-token', resp['access_token'])
       self.assertEqual(exp, resp['expiry'])
 
   def test_no_auth_works(self):
     # If 'task_service_account' is empty, doesn't launch local HTTP server.
     auth_params_path = self.write_auth_params(bot_auth.AuthParams(
         swarming_http_headers={'Authorization': 'Bearer bot-own-token'},
         swarming_http_headers_exp=0,
+        system_service_account='none',
         task_service_account='none'))
     with bot_auth.AuthSystem(auth_params_path) as auth_sys:
       self.assertIsNone(auth_sys.local_auth_context)
 
 
 if __name__ == '__main__':
   fix_encoding.fix_encoding()
   logging.basicConfig(
       level=logging.DEBUG if '-v' in sys.argv else logging.CRITICAL)
   unittest.main()