Workaround to sporadic unit-test failures (#696)

Fixes https://github.com/zalando/patroni/issues/691

tests/test_postgresql.py

@@ -14,7 +14,7 @@ from patroni.postgresql import Postgresql, STATE_REJECT, STATE_NO_RESPONSE
 from patroni.postmaster import PostmasterProcess
 from patroni.utils import RetryFailedError
 from six.moves import builtins
-from threading import Thread
+from threading import Thread, current_thread
 
 
 class MockCursor(object):
@@ -790,10 +790,12 @@ class TestPostgresql(unittest.TestCase):
 
     def test_wait_for_startup(self):
         state = {'sleeps': 0, 'num_rejects': 0, 'final_return': 0}
+        self.__thread_ident = current_thread().ident
 
         def increment_sleeps(*args):
-            print("Sleep")
-            state['sleeps'] += 1
+            if current_thread().ident == self.__thread_ident:
+                print("Sleep")
+                state['sleeps'] += 1
 
         def isready_return(*args):
             ret = 1 if state['sleeps'] < state['num_rejects'] else state['final_return']

tests/test_wale_restore.py

@@ -7,6 +7,7 @@ from patroni.scripts import wale_restore
 from patroni.scripts.wale_restore import WALERestore, main as _main, get_major_version
 from six.moves import builtins
 from test_postgresql import MockConnect, psycopg2_connect
+from threading import current_thread
 
 
 wale_output_header = (
@@ -42,6 +43,13 @@ class TestWALERestore(unittest.TestCase):
                                         '/etc', 100, 100, 1, 0, WALE_TEST_RETRIES)
 
     def test_should_use_s3_to_create_replica(self):
+        self.__thread_ident = current_thread().ident
+        sleeps = [0]
+
+        def mock_sleep(*args):
+            if current_thread().ident == self.__thread_ident:
+                sleeps[0] += 1
+
         self.assertTrue(self.wale_restore.should_use_s3_to_create_replica())
         with patch.object(MockConnect, 'server_version', PropertyMock(return_value=100000)):
             self.assertTrue(self.wale_restore.should_use_s3_to_create_replica())
@@ -55,13 +63,11 @@ class TestWALERestore(unittest.TestCase):
 
             self.assertFalse(self.wale_restore.should_use_s3_to_create_replica())
 
-            with patch('time.sleep', Mock(return_value=None)) as mock_sleep:
+            with patch('time.sleep', mock_sleep):
                 self.wale_restore.no_master = 1
-                assert self.wale_restore.should_use_s3_to_create_replica()
+                self.assertTrue(self.wale_restore.should_use_s3_to_create_replica())
                 # verify retries
-                mock_sleep.assert_has_calls(
-                    [((wale_restore.RETRY_SLEEP_INTERVAL,),)] * WALE_TEST_RETRIES
-                )
+                self.assertEqual(sleeps[0], WALE_TEST_RETRIES)
 
             self.wale_restore.master_connection = ''
             self.assertTrue(self.wale_restore.should_use_s3_to_create_replica())
@@ -104,13 +110,20 @@ class TestWALERestore(unittest.TestCase):
 
     @patch('sys.exit', Mock())
     def test_main(self):
+        self.__thread_ident = current_thread().ident
+        sleeps = [0]
+
+        def mock_sleep(*args):
+            if current_thread().ident == self.__thread_ident:
+                sleeps[0] += 1
+
         with patch.object(WALERestore, 'run', Mock(return_value=0)):
             self.assertEqual(_main(), 0)
 
         with patch.object(WALERestore, 'run', Mock(return_value=1)), \
-                patch('time.sleep', Mock(return_value=None)) as mock_sleep:
+                patch('time.sleep', mock_sleep):
             self.assertEqual(_main(), 1)
-            assert mock_sleep.call_count == WALE_TEST_RETRIES
+            self.assertTrue(sleeps[0], WALE_TEST_RETRIES)
 
     @patch('os.path.isfile', Mock(return_value=True))
     def test_get_major_version(self):