Fix etcd and zookeper interactions with initialize key.

Fix unittests as well.

patroni/dcs.py

@@ -73,7 +73,6 @@ class Cluster(namedtuple('Cluster', 'initialize,leader,last_leader_operation,mem
 class AbstractDCS:
 
     __metaclass__ = abc.ABCMeta
-    initialize_key = '/initialize'
 
     _INITIALIZE = 'initialize'
     _LEADER = 'leader'

patroni/etcd.py

@@ -233,7 +233,7 @@ class Etcd(AbstractDCS):
 
     @catch_etcd_errors
     def initialize(self):
-        return self.client.write(self.client_path(self.initialize_key), self._name, prevExist=False)
+        return self.client.write(self.initialize_path, self._name, prevExist=False)
 
     @catch_etcd_errors
     def delete_leader(self):
@@ -241,7 +241,7 @@ class Etcd(AbstractDCS):
 
     @catch_etcd_errors
     def cancel_initialization(self):
-        return self.client.delete(self.client_path(self.initialize_key), prevValue=self._name)
+        return self.client.delete(self.initialize_path, prevValue=self._name)
 
     def watch(self, timeout):
         # watch on leader key changes if it is defined and current node is not lock owner

patroni/zookeeper.py

@@ -4,7 +4,7 @@ import requests
 import time
 
 from kazoo.client import KazooClient, KazooState
-from kazoo.exceptions import NoNodeError, NodeExistsError
+from kazoo.exceptions import NoNodeError, NodeExistsError, KazooException
 from patroni.dcs import AbstractDCS, Cluster, DCSError, Leader, Member, parse_connection_string
 from patroni.utils import sleep
 from requests.exceptions import RequestException
@@ -222,8 +222,11 @@ class ZooKeeper(AbstractDCS):
 
     def cancel_initialization(self):
         node = self.get_node(self.initialize_path)
-        if node and node == self._name:
-            self.client.delete(self.initialize_path)
+        if node and node[0] == self._name:
+            try:
+                self.client.retry(self.client.delete, self.initialize_path, version=node[1].mzxid)
+            except KazooException:
+                logger.exception("Unable to delete initialize key")
 
     def watch(self, timeout):
         self.cluster_event.wait(timeout)

tests/test_zookeeper.py

@@ -71,8 +71,8 @@ class MockKazooClient:
             if self.leader:
                 return ('foo', ZnodeStat(0, 0, 0, 0, 0, 0, 0, -1, 0, 0, 0))
             return ('foo', ZnodeStat(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0))
-        elif path.endswith(patroni.zookeeper.ZooKeeper.initialize_key):
-            return 'foo'
+        elif path.endswith('/initialize'):
+            return ('foo', ZnodeStat(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0))
 
     def get_children(self, path, watch=None, include_data=False):
         return ['foo', 'bar', 'buzz']
@@ -95,8 +95,8 @@ class MockKazooClient:
                 return
             self.leader = True
             raise Exception
-        elif path.endswith(patroni.zookeeper.ZooKeeper.initialize_key):
-            raise Exception
+        elif path.endswith('/initialize'):
+            raise NoNodeError
 
     def set_hosts(self, hosts, randomize_hosts=None):
         pass
@@ -154,7 +154,7 @@ class TestZooKeeper(unittest.TestCase):
         self.assertFalse(self.zk.initialize())
 
     def test_cancel_initialization(self):
-        self.assertRaises(Exception, self.zk.cancel_initialization)
+        self.zk.cancel_initialization()
 
     def test_touch_member(self):
         self.zk.touch_member('new')