RAI-17360 Expanded retry mechanism to do retries on a ConnectionError (#137)

* expanded retry mechanism to do retries on ConnectionError as well

* updated CHANGELOG and version for new release

Author: Anatoli Kurtsevich

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Changelog
 
+## v0.6.16
+
+* Expanded the retry mechanism for HTTP failures raised as `ConnectionError`.
+
 ## v0.6.15
 
 * Increase auth token expiration buffer from 5s to 60s.

railib/__init__.py

@@ -12,5 +12,5 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-__version_info__ = (0, 6, 15)
+__version_info__ = (0, 6, 16)
 __version__ = ".".join(map(str, __version_info__))

railib/rest.py

@@ -17,8 +17,6 @@
 import json
 import logging
 from os import path
-import socket
-import time
 from urllib.error import URLError
 from urllib.parse import urlencode, urlsplit, quote
 from urllib.request import Request, urlopen
@@ -228,11 +226,8 @@ def _urlopen_with_retry(req: Request, retries: int = 0):
     for attempt in range(attempts):
         try:
             return urlopen(req)
-        except URLError as e:
-            if isinstance(e.reason, socket.timeout):
-                logger.warning(f"Timeout occurred (attempt {attempt + 1}/{attempts}): {req.full_url}")
-            else:
-                logger.warning(f"URLError occurred {e.reason} (attempt {attempt + 1}/{attempts}): {req.full_url}")
+        except (URLError, ConnectionError) as e:
+            logger.warning(f"URL/Connection error occured {req.full_url} (attempt {attempt + 1}/{attempts}). Error message: {str(e)}")
 
             if attempt == attempts - 1:
                 logger.error(f"Failed to connect to {req.full_url} after {attempts} attempt{'s' if attempts > 1 else ''}")

test/test_unit.py

@@ -31,6 +31,9 @@ def test_validation(self):
 @patch('railib.rest.urlopen')
 class TestURLOpenWithRetry(unittest.TestCase):
 
+    WARNING_LOG_PREFIX = "URL/Connection error occured"
+    ERROR_LOG_PREFIX = "Failed to connect to"
+
     def test_successful_response(self, mock_urlopen):
         # Set up the mock urlopen to return a successful response
         mock_response = MagicMock()
@@ -55,7 +58,7 @@ def test_negative_retries(self, _):
 
         self.assertIn("Retries must be a non-negative integer", str(e.exception))
 
-    def test_timeout_retry(self, mock_urlopen):
+    def test_url_error_retry(self, mock_urlopen):
         # Set up the mock urlopen to raise a socket timeout error
         mock_urlopen.side_effect = URLError(socket.timeout())
 
@@ -66,26 +69,27 @@ def test_timeout_retry(self, mock_urlopen):
 
         self.assertEqual(mock_urlopen.call_count, 3)  # Expect 1 original call and 2 calls for retries
         self.assertEqual(len(log.output), 4)  # Expect 3 log messages for retries and 1 for failure to connect
-        self.assertIn('Timeout occurred', log.output[0])
-        self.assertIn('Timeout occurred', log.output[1])
-        self.assertIn('Timeout occurred', log.output[2])
-        self.assertIn('Failed to connect to', log.output[3])
+        self.assertIn(TestURLOpenWithRetry.WARNING_LOG_PREFIX, log.output[0])
+        self.assertIn(TestURLOpenWithRetry.WARNING_LOG_PREFIX, log.output[1])
+        self.assertIn(TestURLOpenWithRetry.WARNING_LOG_PREFIX, log.output[2])
+        self.assertIn(TestURLOpenWithRetry.ERROR_LOG_PREFIX, log.output[3])
 
-    def test_other_error_retry(self, mock_urlopen):
-        # Set up the mock urlopen to raise a non-timeout URLError
-        mock_urlopen.side_effect = URLError('Some other error')
+    def test_connection_error_retry(self, mock_urlopen):
+        # Set up the mock urlopen to raise a error that is subclass of ConnectonError
+        mock_urlopen.side_effect = ConnectionResetError("connection reset by peer")
 
         req = Request('https://example.com')
         with self.assertLogs() as log:
             with self.assertRaises(Exception):
-                _urlopen_with_retry(req, retries=2)
+                _urlopen_with_retry(req, 2)
 
-        self.assertEqual(mock_urlopen.call_count, 3)  # Expect 3 calls for retries
+        self.assertEqual(mock_urlopen.call_count, 3)  # Expect 1 original call and 2 calls for retries
         self.assertEqual(len(log.output), 4)  # Expect 3 log messages for retries and 1 for failure to connect
-        self.assertIn('URLError occurred', log.output[0])
-        self.assertIn('URLError occurred', log.output[1])
-        self.assertIn('URLError occurred', log.output[2])
-        self.assertIn('Failed to connect to', log.output[3])
+        self.assertIn(TestURLOpenWithRetry.WARNING_LOG_PREFIX, log.output[0])
+        self.assertIn(TestURLOpenWithRetry.WARNING_LOG_PREFIX, log.output[1])
+        self.assertIn(TestURLOpenWithRetry.WARNING_LOG_PREFIX, log.output[2])
+        self.assertIn(TestURLOpenWithRetry.ERROR_LOG_PREFIX, log.output[3])
+
 
 
 if __name__ == '__main__':