Don't try to resolve hostnames when option is disabled

pyexasol/connection.py

@@ -34,7 +34,7 @@
 class Host(NamedTuple):
  """This represents a resolved host name with its IP address and port number."""
  hostname: str
- ip_address: str
+ ip_address: Optional[str]
  port: int
  fingerprint: Optional[str]
 
@@ -670,10 +670,7 @@ def _init_ws(self):
  try:
  self._ws = self._create_websocket_connection(hostname, ipaddr, port)
  except Exception as e:
- self.logger.debug(f'Failed to connect [{ipaddr}:{port}]: {e}')
-
  failed_attempts += 1
-
  if failed_attempts == len(dsn_items):
  raise ExaConnectionFailedError(self, 'Could not connect to Exasol: ' + str(e)) from e
  else:
@@ -698,11 +695,17 @@ def _create_websocket_connection(self, hostname:str, ipaddr:str, port:int) -> we
 
  connection_string = self._get_websocket_connection_string(hostname, ipaddr, port)
  self.logger.debug(f"Connection attempt {connection_string}")
- return websocket.create_connection(connection_string, **ws_options)
-
+ try:
+ return websocket.create_connection(connection_string, **ws_options)
+ except Exception as e:
+ self.logger.debug(f'Failed to connect [{connection_string}]: {e}')
+ raise e
 
- def _get_websocket_connection_string(self, hostname:str, ipaddr:str, port:int) -> str:
- host = ipaddr if self.options["resolve_hostnames"] else hostname
+ def _get_websocket_connection_string(self, hostname:str, ipaddr:Optional[str], port:int) -> str:
+ host = hostname
+ if self.options["resolve_hostnames"]:
+ assert ipaddr is not None
+ host = ipaddr
  if self.options["encryption"]:
  return f"wss://{host}:{port}"
  else:
@@ -810,7 +813,11 @@ def _process_dsn(self, dsn: str) -> list[Host]:
  result.extend(self._resolve_hostname(hostname, current_port, current_fingerprint))
  # Just a single hostname or single IP address
  else:
- result.extend(self._resolve_hostname(m.group('hostname_prefix'), current_port, current_fingerprint))
+ hostname = m.group('hostname_prefix')
+ if self.options["resolve_hostnames"]:
+ result.extend(self._resolve_hostname(hostname, current_port, current_fingerprint))
+ else:
+ result.append(Host(hostname, None, current_port, current_fingerprint))
 
  random.shuffle(result)
 

test/integration/connection_test.py

@@ -64,6 +64,18 @@ def test_process_empty_dsn_fails(connection_mock, empty_dsn):
  with pytest.raises(ExaConnectionDsnError, match="Connection string is empty"):
  connection_mock.process_dsn(empty_dsn)
 
+def test_process_dsn_resolves_hostname_to_ip_address(connection_mock):
+ connection_mock.simulate_resolve_hostnames([("host1", [], ["ip1"])])
+ actual = connection_mock.process_dsn("host1:1234")
+ expected = [Host("host1", "ip1", 1234, None)]
+ assert expected == actual
+
+def test_process_dsn_does_not_resolve_hostname(connection_mock):
+ connection_mock.connection.options["resolve_hostnames"] = False
+ actual = connection_mock.process_dsn("host1:1234")
+ expected = [Host("host1", None, 1234, None)]
+ assert expected == actual
+
 def test_process_dsn_shuffles_hosts(connection_mock):
  dsn = "host1:1234,host2:4321"
  def resolve_hostname(con):