urllib3.exceptions.HTTPError fixes for python 3.5.1

Somehow when you import only urllib3 it's not possible work with
urllib3.exceptions.HTTPError exception (it looks like it is imported
from some other place. from urllib3.exceptions import HTTPError solves
the problem.

patroni/etcd.py

@@ -6,13 +6,13 @@ import random
 import requests
 import socket
 import time
-import urllib3
 
 from dns.exception import DNSException
 from dns import resolver
 from patroni.dcs import AbstractDCS, Cluster, Failover, Leader, Member
 from patroni.exceptions import DCSError
 from patroni.utils import Retry, RetryFailedError, sleep
+from urllib3.exceptions import HTTPError, ReadTimeoutError
 from requests.exceptions import RequestException
 from six.moves.http_client import HTTPException
 
@@ -55,9 +55,9 @@ class Client(etcd.Client):
             response = request_executor(method, url, fields=fields, **kwargs)
             response.data.decode('utf-8')
             self._check_cluster_id(response)
-        except (urllib3.exceptions.HTTPError, HTTPException, socket.error) as e:
+        except (HTTPError, HTTPException, socket.error, socket.timeout) as e:
             if (isinstance(fields, dict) and fields.get("wait") == "true" and
-                    isinstance(e, urllib3.exceptions.ReadTimeoutError)):
+                    isinstance(e, ReadTimeoutError)):
                 logger.debug("Watch timed out.")
                 raise etcd.EtcdWatchTimedOut("Watch timed out: {0}".format(e), cause=e)
             logger.error("Request to server %s failed: %r", self._base_uri, e)
@@ -302,13 +302,12 @@ class Etcd(AbstractDCS):
     def watch(self, timeout):
         cluster = self.cluster
         # watch on leader key changes if it is defined and current node is not lock owner
-        if cluster and cluster.leader and cluster.leader.name != self._name:
+        if cluster and cluster.leader and cluster.leader.name != self._name and cluster.leader.index:
             end_time = time.time() + timeout
-            index = cluster.leader.index
 
-            while index and timeout >= 1:  # when timeout is too small urllib3 doesn't have enough time to connect
+            while timeout >= 1:  # when timeout is too small urllib3 doesn't have enough time to connect
                 try:
-                    self._client.watch(self.leader_path, index=index + 1, timeout=timeout + 0.5)
+                    self._client.watch(self.leader_path, index=cluster.leader.index + 1, timeout=timeout + 0.5)
                     # Synchronous work of all cluster members with etcd is less expensive
                     # than reestablishing http connection every time from every replica.
                     return True

tests/test_etcd.py

@@ -1,15 +1,15 @@
 import etcd
 import json
 import requests
-import urllib3
 import socket
 import unittest
 
 from dns.exception import DNSException
 from mock import Mock, patch
-from patroni.dcs import Cluster
+from patroni.dcs import Cluster, AbstractDCS
 from patroni.etcd import Client, Etcd, EtcdError
 from patroni.exceptions import DCSError
+from urllib3.exceptions import ReadTimeoutError
 
 
 class MockResponse(object):
@@ -61,8 +61,6 @@ def etcd_watch(self, key, index=None, timeout=None, recursive=None):
         return etcd.EtcdResult('delete', {})
     elif timeout == 10.0:
         raise etcd.EtcdException
-    elif index == 20729:
-        return etcd.EtcdResult('set', {'value': 'postgresql1', 'modifiedIndex': index + 1})
 
 
 def etcd_write(self, key, value, **kwargs):
@@ -132,7 +130,7 @@ def socket_getaddrinfo(*args):
 
 def http_request(method, url, **kwargs):
     if url == 'http://localhost:2379/timeout':
-        raise urllib3.exceptions.ReadTimeoutError(None, None, None)
+        raise ReadTimeoutError(None, None, None)
     if url == 'http://localhost:2379/':
         return MockResponse()
     raise socket.error
@@ -248,8 +246,8 @@ class TestEtcd(unittest.TestCase):
         self.etcd.get_cluster()
         self.etcd.watch(1.5)
         self.etcd.watch(4.5)
-        self.etcd.watch(9.5)
-        self.etcd.watch(100)
+        with patch.object(AbstractDCS, 'watch', Mock()):
+            self.etcd.watch(9.5)
 
     @patch('patroni.etcd.Etcd.retry', Mock(side_effect=AttributeError("foo")))
     def test_other_exceptions(self):