Automatically retry ConnectionErrors

CHANGES.rst

@@ -4,6 +4,15 @@ Change Log
 prawcore follows `semantic versioning <http://semver.org/>`_ with the exception
 that deprecations will not be announced by a minor release.
 
+Unreleased
+----------
+
+**Added**
+
+* ``ConnectionErrors`` exceptios are automatically retried. This handles
+  ``Connection Reset by Peer`` issues that appear to occur somewhat frequently
+  when running on Amazon EC2.
+
 0.9.0 (2017-03-11)
 ------------------
 

prawcore/const.py

@@ -1,7 +1,7 @@
 """Constants for the prawcore package."""
 import os
 
-__version__ = '0.9.0'
+__version__ = '0.10.0rc1'
 
 ACCESS_TOKEN_PATH = '/api/v1/access_token'
 AUTHORIZATION_PATH = '/api/v1/authorize'

prawcore/sessions.py

@@ -5,7 +5,7 @@
 import time
 
 from requests.compat import urljoin
-from requests.exceptions import ChunkedEncodingError
+from requests.exceptions import ChunkedEncodingError, ConnectionError
 from requests.status_codes import codes
 
 from .auth import BaseAuthorizer
@@ -20,7 +20,7 @@
 class Session(object):
     """The low-level connection interface to reddit's API."""
 
-    RETRY_EXCEPTIONS = (ChunkedEncodingError,)
+    RETRY_EXCEPTIONS = (ChunkedEncodingError, ConnectionError)
     RETRY_STATUSES = {520, 522, codes['bad_gateway'], codes['gateway_timeout'],
                       codes['internal_server_error'],
                       codes['service_unavailable']}

tests/test_sessions.py

@@ -7,7 +7,7 @@
 from betamax import Betamax
 from mock import Mock, patch
 from prawcore.exceptions import RequestException
-from requests.exceptions import ChunkedEncodingError
+from requests.exceptions import ChunkedEncodingError, ConnectionError
 from testfixtures import LogCapture
 
 from .config import (CLIENT_ID, CLIENT_SECRET, REFRESH_TOKEN, REQUESTOR,
@@ -97,6 +97,34 @@ def test_request__chunked_encoding_retry(self, mock_session):
         self.assertIs(exception, context_manager.exception.original_exception)
         self.assertEqual(3, session_instance.request.call_count)
 
+    @patch('requests.Session')
+    def test_request__connection_error_retry(self, mock_session):
+        session_instance = mock_session.return_value
+
+        # Handle Auth
+        response_dict = {'access_token': '', 'expires_in': 99, 'scope': ''}
+        session_instance.request.return_value = Mock(
+            headers={}, json=lambda: response_dict, status_code=200)
+        requestor = prawcore.Requestor('prawcore:test (by /u/bboe)')
+        authorizer = readonly_authorizer(requestor=requestor)
+        session_instance.request.reset_mock()
+
+        # Fail on subsequent request
+        exception = ConnectionError()
+        session_instance.request.side_effect = exception
+
+        expected = ('prawcore', 'WARNING',
+                    'Retrying due to ConnectionError() status: GET '
+                    'https://oauth.reddit.com/')
+
+        with LogCapture(level=logging.WARNING) as log_capture:
+            with self.assertRaises(RequestException) as context_manager:
+                prawcore.Session(authorizer).request('GET', '/')
+            log_capture.check(expected, expected)
+        self.assertIsInstance(context_manager.exception, RequestException)
+        self.assertIs(exception, context_manager.exception.original_exception)
+        self.assertEqual(3, session_instance.request.call_count)
+
     def test_request__get(self):
         with Betamax(REQUESTOR).use_cassette('Session_request__get'):
             session = prawcore.Session(readonly_authorizer())