Merge pull request #5 from marselester/exc-log

Exception logging

Author: marselester

README.rst

@@ -27,6 +27,11 @@ Usage example:
 
     logger.info('Sign up', extra={'referral_code': '52d6ce'})
 
+    try:
+        raise ValueError('something wrong')
+    except ValueError:
+        logger.error('Request failed', exc_info=True)
+
 The log file will contain the following log record (inline).
 
 .. code-block:: json
@@ -36,6 +41,11 @@ The log file will contain the following log record (inline).
         "time": "2015-09-01T06:06:26.524448",
         "referral_code": "52d6ce"
     }
+    {
+        "message": "Request failed",
+        "time": "2015-09-01T06:06:26.524449",
+        "exc_info": "Traceback (most recent call last): ..."
+    }
 
 JSON libraries
 --------------

json_log_formatter/__init__.py

@@ -55,6 +55,7 @@ class JSONFormatter(logging.Formatter):
         }
 
     """
+
     json_lib = json
 
     def format(self, record):
@@ -70,9 +71,10 @@ def format(self, record):
         return self.to_json(mutated_record)
 
     def to_json(self, record):
-        """Convert record dict to a json string
+        """Converts record dict to a JSON string.
 
         Override this method to change the way dict is converted to JSON.
+
         """
         return self.json_lib.dumps(record)
 
@@ -104,6 +106,10 @@ def json_record(self, message, extra, record):
         extra['message'] = message
         if 'time' not in extra:
             extra['time'] = datetime.utcnow()
+
+        if record.exc_info:
+            extra['exc_info'] = self.formatException(record.exc_info)
+
         return extra
 
     def mutate_json_record(self, json_record):

tests.py

@@ -64,6 +64,17 @@ def test_message_and_time_and_extra_are_in_json_record_when_extra_is_provided(se
         ])
         self.assertEqual(set(json_record), expected_fields)
 
+    def test_exc_info_is_logged(self):
+        try:
+            raise ValueError('something wrong')
+        except ValueError:
+            logger.error('Request failed', exc_info=True)
+        json_record = json.loads(log_buffer.getvalue())
+        self.assertIn(
+            'Traceback (most recent call last)',
+            json_record['exc_info']
+        )
+
 
 class MutatingFormatter(JSONFormatter):
     def mutate_json_record(self, json_record):

tox.ini

@@ -7,4 +7,4 @@ deps=
     ujson
     simplejson
 commands=
-    pytest tests.py
+    pytest -s tests.py