autodetect the host role during start from the existence of recovery.conf.

helpers/postgresql.py

@@ -245,6 +245,10 @@ class Postgresql:
         ret = subprocess.call(self._pg_ctl + ['start', '-o', self.server_options()]) == 0
         ret and self.load_replication_slots()
         self.save_configuration_files()
+        if os.path.exists(self.recovery_conf):
+            self.on_change_callback('replica')
+        else:
+            self.on_change_callback('master')
         return ret
 
     def stop(self):