Create raft data_dir if necessary (#1846)

Close #1760

patroni/dcs/raft.py

@@ -5,6 +5,7 @@ import threading
 import time
 
 from patroni.dcs import AbstractDCS, ClusterConfig, Cluster, Failover, Leader, Member, SyncState, TimelineHistory
+from ..utils import validate_directory
 from pysyncobj import SyncObj, SyncObjConf, replicated, FAIL_REASON
 from pysyncobj.transport import Node, TCPTransport, CONNECTION_STATE
 
@@ -275,6 +276,11 @@ class Raft(AbstractDCS):
                 partner_addrs.append(self_addr)
             self_addr = None
 
+        # Create raft data_dir if necessary
+        raft_data_dir = config.get('data_dir', '')
+        if raft_data_dir != '':
+            validate_directory(raft_data_dir)
+
         ready_event = threading.Event()
         file_template = os.path.join(config.get('data_dir', ''), (self_addr or ''))
         conf = SyncObjConf(password=config.get('password'), appendEntriesUseBatch=False,

patroni/utils.py

@@ -1,3 +1,4 @@
+import errno
 import json.decoder as json_decoder
 import logging
 import os
@@ -461,7 +462,8 @@ def validate_directory(d, msg="{} {}"):
             os.makedirs(d)
         except OSError as e:
             logger.error(e)
-            raise PatroniException(msg.format(d, "couldn't create the directory"))
+            if e.errno != errno.EEXIST:
+                raise PatroniException(msg.format(d, "couldn't create the directory"))
     elif os.path.isdir(d):
         try:
             fd, tmpfile = tempfile.mkstemp(dir=d)