Print more helpful errors on config parsing failure

Signed-off-by: Jeremy Cline <jcline@redhat.com>

fedora_messaging/config.py

@@ -404,8 +404,9 @@ def load_config(self, config_path=None):
                     for key in file_config:
                         config[key.lower()] = file_config[key]
                 except pytoml.core.TomlError as e:
-                    _log.error('Failed to parse {}: {}'.format(config_path, str(e)))
-                    raise exceptions.ConfigurationException(e)
+                    msg = 'Failed to parse {}: error at line {}, column {}'.format(
+                            config_path, e.line, e.col)
+                    raise exceptions.ConfigurationException(msg)
         else:
             _log.info('The configuration file, {}, does not exist.'.format(config_path))
 

fedora_messaging/exceptions.py

@@ -8,6 +8,12 @@ class BaseException(Exception):
 class ConfigurationException(BaseException):
     """Raised when there's an invalid configuration setting"""
 
+    def __init__(self, message):
+        self.message = message
+
+    def __str__(self):
+        return 'Configuration error: ' + self.message
+
 
 class PublishException(BaseException):
     """Base class for exceptions related to publishing."""

fedora_messaging/tests/unit/test_config.py

@@ -120,15 +120,13 @@ def test_invalid_key(self, mock_exists):
         self.assertRaises(ConfigurationException, config.load_config)
 
     @mock.patch('fedora_messaging.config.open', mock.mock_open(read_data='Ni!'))
-    @mock.patch('fedora_messaging.config._log', autospec=True)
     @mock.patch('fedora_messaging.config.os.path.exists', return_value=True)
-    def test_bad_config_file(self, mock_exists, mock_log):
+    def test_bad_config_file(self, mock_exists):
         """Assert an invalid TOML file raises a ConfigurationException."""
-        self.assertRaises(ConfigurationException, msg_config.LazyConfig().load_config)
-        mock_log.info.assert_called_once_with(
-            'Loading configuration from /etc/fedora-messaging/config.toml')
-        error = 'Failed to parse /etc/fedora-messaging/config.toml: <string>(1, 1): msg'
-        self.assertEqual(error, mock_log.error.call_args_list[0][0][0])
+        with self.assertRaises(ConfigurationException) as cm:
+            msg_config.LazyConfig().load_config()
+        error = 'Failed to parse /etc/fedora-messaging/config.toml: error at line 1, column 1'
+        self.assertEqual(error, cm.exception.message)
 
     @mock.patch('fedora_messaging.config.open', mock.mock_open(read_data=partial_config))
     @mock.patch('fedora_messaging.config._log', autospec=True)