From bc0f9f522ebad5c7cf2b95b9721ade62481059b7 Mon Sep 17 00:00:00 2001
From: Polina Bungina <bungina@gmail.com>
Date: Thu, 27 Jul 2023 20:46:36 +0200
Subject: [PATCH] Refactor do_POST_failover checks

---
 patroni/api.py    | 25 +++++++++++++------------
 tests/test_api.py |  1 +
 2 files changed, 14 insertions(+), 12 deletions(-)

diff --git a/patroni/api.py b/patroni/api.py
index b9626ecf..0702cff9 100644
--- a/patroni/api.py
+++ b/patroni/api.py
@@ -1018,24 +1018,25 @@ class RestApiHandler(BaseHTTPRequestHandler):
         logger.info("received %s request with leader=%s candidate=%s scheduled_at=%s",
                     action, leader, candidate, scheduled_at)
 
-        if action == 'failover':
-            if not candidate:
-                data = 'Failover could be performed only to a specific candidate'
-            elif scheduled_at:
-                data = "Failover can't be scheduled"
+        if action == 'failover' and not candidate:
+            data = 'Failover could be performed only to a specific candidate'
         elif action == 'switchover' and not leader:
             data = 'Switchover could be performed only from a specific leader'
 
         if not data and scheduled_at:
-            if not leader:
-                data = 'Scheduled {0} is possible only from a specific leader'.format(action)
-            if not data and global_config.is_paused:
-                data = "Can't schedule {0} in the paused state".format(action)
-            if not data:
+            if action == 'failover':
+                data = "Failover can't be scheduled"
+            elif global_config.is_paused:
+                data = "Can't schedule switchover in the paused state"
+            else:
                 (status_code, data, scheduled_at) = self.parse_schedule(scheduled_at, action)
 
         if not data and global_config.is_paused and not candidate:
-            data = action.title() + ' is possible only to a specific candidate in a paused state'
+            data = 'Switchover is possible only to a specific candidate in a paused state'
+
+        if action == 'failover' and leader:
+            logger.warning('received failover request with leader specifed - performing switchover')
+            action = 'switchover'
 
         if not data and not scheduled_at:
             data = self.is_failover_possible(cluster, leader, candidate, action)
@@ -1052,7 +1053,7 @@ class RestApiHandler(BaseHTTPRequestHandler):
                     status_code, data = self.poll_failover_result(cluster.leader and cluster.leader.name,
                                                                   candidate, action)
             else:
-                data = 'failed to write {0} key into DCS'.format(action)
+                data = 'failed to write failover key into DCS'
                 status_code = 503
         # pyright thinks ``status_code`` can be ``None`` because ``parse_schedule`` call may return ``None``. However,
         # if that's the case, ``status_code`` will be overwritten somewhere between ``parse_schedule`` and
diff --git a/tests/test_api.py b/tests/test_api.py
index f9d0b1c1..837cdbaf 100644
--- a/tests/test_api.py
+++ b/tests/test_api.py
@@ -580,6 +580,7 @@ class TestRestApiHandler(unittest.TestCase):
         post = 'POST /failover HTTP/1.0' + self._authorization + '\nContent-Length: '
         MockRestApiServer(RestApiHandler, post + '14\n\n{"leader":"1"}')
         MockRestApiServer(RestApiHandler, post + '37\n\n{"candidate":"2","scheduled_at": "1"}')
+        MockRestApiServer(RestApiHandler, post + '30\n\n{"leader":"1","candidate":"2"}')
 
     @patch.object(MockHa, 'is_leader', Mock(return_value=True))
     def test_do_POST_citus(self):