Move the recovery.conf based role check to a function.

patroni/postgresql.py

@@ -79,7 +79,7 @@ def __init__(self, config):
 
         self._state = 'stopped'
         self._state_lock = Lock()
-        self._role = 'replica' if os.path.exists(self.recovery_conf) else 'master'
+        self._role = self.get_postgres_role_from_data_directory()
         self._role_lock = Lock()
 
         if self.is_running():
@@ -124,6 +124,9 @@ def get_local_address(self):
                 break
         return local_address + ':' + self.port
 
+    def get_postgres_role_from_data_directory(self):
+        return 'replica' if os.path.exists(self.recovery_conf) else 'master'
+
     @property
     def _connect_kwargs(self):
         r = parseurl('postgres://{0}/postgres'.format(self.local_address))
@@ -347,7 +350,7 @@ def start(self, block_callbacks=False):
             logger.error('Cannot start PostgreSQL because one is already running.')
             return True
 
-        self.set_role('replica' if os.path.exists(self.recovery_conf) else 'master')
+        self.set_role(self.get_postgres_role_from_data_directory())
         if os.path.exists(self.postmaster_pid):
             os.remove(self.postmaster_pid)
             logger.info('Removed %s', self.postmaster_pid)