Emit warning log in object replicator

When the object-replicator encounters handoffs_first and
handoff_delete options as enabled it should emit a log
warning indicating that it should be changed back to the
default before the next "normal" rebalance.

Closes-Bug: #1457262

Change-Id: If9dc2796c18ed3cf13da920831e2d5c2ae9f12a0

swift/obj/replicator.py

@@ -53,13 +53,13 @@ class ObjectReplicator(Daemon):
     caller to do this in a loop.
     """
 
-    def __init__(self, conf):
+    def __init__(self, conf, logger=None):
         """
         :param conf: configuration object obtained from ConfigParser
         :param logger: logging object
         """
         self.conf = conf
-        self.logger = get_logger(conf, log_route='object-replicator')
+        self.logger = logger or get_logger(conf, log_route='object-replicator')
         self.devices_dir = conf.get('devices', '/srv/node')
         self.mount_check = config_true_value(conf.get('mount_check', 'true'))
         self.vm_test_mode = config_true_value(conf.get('vm_test_mode', 'no'))
@@ -99,6 +99,10 @@ class ObjectReplicator(Daemon):
                                                          False))
         self.handoff_delete = config_auto_int_value(
             conf.get('handoff_delete', 'auto'), 0)
+        if any((self.handoff_delete, self.handoffs_first)):
+            self.logger.warn('handoffs_first and handoff_delete should be'
+                             ' changed back to the default before the next'
+                             ' normal rebalance')
         self._diskfile_mgr = DiskFileManager(conf, self.logger)
 
     # Just exists for doc anchor point

test/unit/obj/test_replicator.py

@@ -184,6 +184,23 @@ class TestObjectReplicator(unittest.TestCase):
     def tearDown(self):
         rmtree(self.testdir, ignore_errors=1)
 
+    def test_handoff_replication_setting_warnings(self):
+        conf = {'handoffs_first': 'true'}
+        replicator = object_replicator.ObjectReplicator(
+            conf, logger=self.logger)
+        self.assertTrue(replicator.handoffs_first)
+        log_message = 'handoffs_first and handoff_delete should'\
+                      ' be changed back to the default before the'\
+                      ' next normal rebalance'
+        expected = [log_message]
+        self.assertEqual(self.logger.get_lines_for_level('warning'), expected)
+        conf = {'handoff_delete': '2'}
+        replicator = object_replicator.ObjectReplicator(
+            conf, logger=self.logger)
+        self.assertEqual(replicator.handoff_delete, 2)
+        expected.append(log_message)
+        self.assertEqual(self.logger.get_lines_for_level('warning'), expected)
+
     def _write_disk_data(self, disk_name):
         os.mkdir(os.path.join(self.devices, disk_name))
         objects = os.path.join(self.devices, disk_name,