[executor] Log warning when using a legacy algorithm

beat/backend/python/executor.py

@@ -164,6 +164,9 @@ class Executor(object):
                 return False
 
         else:
+            if self.algorithm.type == Algorithm.LEGACY:
+                logger.warning("%s is using LEGACY I/O API, please upgrade this algorithm as soon as possible" % self.algorithm.name)
+
             while self.input_list.hasMoreData():
                 main_group = self.input_list.main_group
                 main_group.restricted_access = False

beat/backend/python/test/test_executor.py

@@ -27,6 +27,7 @@
 
 
 import unittest
+import logging
 import tempfile
 import simplejson
 import os
@@ -46,6 +47,7 @@ from ..helpers import convert_experiment_configuration_to_container
 from ..helpers import AccessMode
 
 from . import prefix
+from .mocks import MockLoggingHandler
 
 
 CONFIGURATION = {
@@ -164,8 +166,16 @@ class TestExecutor(unittest.TestCase):
 
 
     def test_legacy_echo_1(self):
+        log_handler = MockLoggingHandler(level='DEBUG')
+        logging.getLogger().addHandler(log_handler)
+        log_messages = log_handler.messages
+
         self.process('legacy/echo/1')
 
+        info_len = len(log_messages['warning'])
+        self.assertEqual(info_len, 1)
+        self.assertEqual(log_messages['warning'][info_len - 1], 'legacy/echo/1 is using LEGACY I/O API, please upgrade this algorithm as soon as possible')
+
 
     def test_sequential_echo_1(self):
         self.process('sequential/echo/1')