Catch NTPExceptions when requesting time from timeserver

Fixes #256. When the request times out, this exception is thrown. For
now, just default to the local time. The timeout parameter in the
request() function of the NTPClient can also be adjusted. This can be
extended for (hopefully) better reliability of the NTP request.

lib/utils.py

@@ -73,7 +73,7 @@ def get_current_time() -> datetime:
 
     try:
         response = c.request(NTP_SERVER, version=3)
-    except socket.gaierror:
+    except (socket.gaierror, ntplib.NTPException):
         logger.debug("Error requesting time from NTP server. Using local time")
         return datetime.utcnow()
 

tests/unit/test_utils.py

@@ -86,8 +86,11 @@ def test_get_current_time_returns_a_datetime_from_ntp_server(mocker: MockerFixtu
     assert utils.get_current_time() == datetime(1999, 12, 31, 23, 59, 59)
 
 
-def test_get_current_time_returns_local_datetime_on_failed_request(mocker: MockerFixture) -> None:
-    mocker.patch("ntplib.NTPClient.request", side_effect=socket.gaierror)
+@pytest.mark.parametrize("exception", [socket.gaierror, ntplib.NTPException])
+def test_get_current_time_returns_local_datetime_on_failed_request(
+    mocker: MockerFixture, exception: Exception
+) -> None:
+    mocker.patch("ntplib.NTPClient.request", side_effect=exception)
     mock_datetime = mocker.patch("lib.utils.datetime")
     mock_datetime.utcnow.return_value = datetime(1999, 12, 31, 18, 59, 59)