Merge pull request #1447 from cisagov/es/1415-epp-retry

#1415 Retry EPP connection pool on Transport Error

src/epplibwrapper/client.py

@@ -17,7 +17,7 @@ except ImportError:
 from django.conf import settings
 
 from .cert import Cert, Key
-from .errors import LoginError, RegistryError
+from .errors import ErrorCode, LoginError, RegistryError
 from .socket import Socket
 from .utility.pool import EPPConnectionPool
 
@@ -115,7 +115,7 @@ class EPPLibWrapper:
         except TransportError as err:
             message = f"{cmd_type} failed to execute due to a connection error."
             logger.error(f"{message} Error: {err}", exc_info=True)
-            raise RegistryError(message) from err
+            raise RegistryError(message, code=ErrorCode.TRANSPORT_ERROR) from err
         except LoginError as err:
             # For linter due to it not liking this line length
             text = "failed to execute due to a registry login error."
@@ -163,7 +163,8 @@ class EPPLibWrapper:
             try:
                 return self._send(command)
             except RegistryError as err:
-                if err.should_retry() and counter < 3:
+                if counter < 3 and (err.should_retry() or err.is_transport_error()):
+                    logger.info(f"Retrying transport error. Attempt #{counter+1} of 3.")
                     counter += 1
                     sleep((counter * 50) / 1000)  # sleep 50 ms to 150 ms
                 else:  # don't try again

src/epplibwrapper/errors.py

@@ -4,13 +4,15 @@ from enum import IntEnum
 class ErrorCode(IntEnum):
     """
     Overview of registry response codes from RFC 5730. See RFC 5730 for full text.
-
+        - 0 System connection error
         - 1000 - 1500 Success
         - 2000 - 2308 Registrar did something silly
         - 2400 - 2500 Registry did something silly
         - 2501 - 2502 Something malicious or abusive may have occurred
     """
 
+    TRANSPORT_ERROR = 0
+
     COMMAND_COMPLETED_SUCCESSFULLY = 1000
     COMMAND_COMPLETED_SUCCESSFULLY_ACTION_PENDING = 1001
     COMMAND_COMPLETED_SUCCESSFULLY_NO_MESSAGES = 1300
@@ -67,6 +69,9 @@ class RegistryError(Exception):
     def should_retry(self):
         return self.code == ErrorCode.COMMAND_FAILED
 
+    def is_transport_error(self):
+        return self.code == ErrorCode.TRANSPORT_ERROR
+
     # connection errors have error code of None and [Errno 99] in the err message
     def is_connection_error(self):
         return self.code is None