RestApiHandler._patch_config returns True if configuration was changed

patroni/api.py

@@ -110,13 +110,22 @@ class RestApiHandler(BaseHTTPRequestHandler):
 
     @staticmethod
     def _patch_config(config, data):
+        is_changed = False
         for name, value in data.items():
-            if isinstance(value, dict) and name in config:
-                RestApiHandler._patch_config(config[name], value)
-            elif value is None:
-                config.pop(name, None)
+            if value is None:
+                if config.pop(name, None) is not None:
+                    is_changed = True
+            elif name in config:
+                if isinstance(value, dict):
+                    if RestApiHandler._patch_config(config[name], value):
+                        is_changed = True
+                elif str(config[name]) != str(value):
+                    config[name] = value
+                    is_changed = True
             else:
                 config[name] = value
+                is_changed = True
+        return is_changed
 
     @check_auth
     def do_PATCH_config(self):
@@ -124,8 +133,7 @@ class RestApiHandler(BaseHTTPRequestHandler):
         request = json.loads(self.rfile.read(content_length).decode('utf-8'))
         cluster = self.server.patroni.ha.dcs.get_cluster()
         data = cluster.config.data.copy()
-        RestApiHandler._patch_config(data, request)
-        if data != cluster.config.data:
+        if RestApiHandler._patch_config(data, request):
             self.server.patroni.ha.dcs.set_config_value(json.dumps(data, separators=(',', ':')), cluster.config.index)
             self._write_json_response(200, data)
         else:

tests/test_api.py

@@ -1,3 +1,4 @@
+import json
 import psycopg2
 import unittest
 
@@ -123,11 +124,14 @@ class TestRestApiHandler(unittest.TestCase):
 
     @patch.object(MockHa, 'dcs')
     def test_do_PATCH_config(self, mock_dcs):
-        mock_dcs.get_cluster.return_value.config = \
-            ClusterConfig.from_node(1, '{"postgresql": {"use_slots": false, "parameters": {"wal_level": "logical"}}}')
+        config = {'postgresql': {'use_slots': False, 'use_pg_rewind': True, 'parameters': {'wal_level': 'logical'}}}
+        mock_dcs.get_cluster.return_value.config = ClusterConfig.from_node(1, json.dumps(config))
         request = 'PATCH /config HTTP/1.0' + self._authorization + '\nContent-Length: '
         self.assertIsNotNone(MockRestApiServer(RestApiHandler, request + '2\n\n{}'))
-        MockRestApiServer(RestApiHandler, request + '59\n\n{"ttl":5,"use_slots":true,"postgresql":{"parameters":null}}')
+        config['ttl'] = 5
+        config['postgresql'].update({'use_slots': True, "parameters": None})
+        config = json.dumps(config)
+        MockRestApiServer(RestApiHandler, request + str(len(config)) + '\n\n' + config)
 
     @patch.object(MockPatroni, 'sighup_handler', Mock(side_effect=Exception))
     def test_do_POST_reload(self):