Make json formatting optional

fixes #96

Author: arcivanov

fluent/handler.py

@@ -26,9 +26,12 @@ class FluentRecordFormatter(logging.Formatter, object):
     :param datefmt: strftime()-compatible date/time format string.
     :param style: '%', '{' or '$' (used only with Python 3.2 or above)
     :param fill_missing_fmt_key: if True, do not raise a KeyError if the format
-        key is not found. Put None if not found.s
+        key is not found. Put None if not found.
+    :param format_json: if True, will attempt to parse message as json. If not,
+        will use message as-is. Defaults to True
     """
-    def __init__(self, fmt=None, datefmt=None, style='%', fill_missing_fmt_key=False):
+
+    def __init__(self, fmt=None, datefmt=None, style='%', fill_missing_fmt_key=False, format_json=True):
         super(FluentRecordFormatter, self).__init__(None, datefmt)
 
         if sys.version_info[0:2] >= (3, 2) and style != '%':
@@ -57,6 +60,11 @@ def __init__(self, fmt=None, datefmt=None, style='%', fill_missing_fmt_key=False
         else:
             self._fmt_dict = fmt
 
+        if format_json:
+            self._format_msg = self._format_msg_json
+        else:
+            self._format_msg = self._format_msg_default
+
         self.hostname = socket.gethostname()
 
         self.fill_missing_fmt_key = fill_missing_fmt_key
@@ -107,18 +115,23 @@ def _structuring(self, data, record):
         if isinstance(msg, dict):
             self._add_dic(data, msg)
         elif isinstance(msg, basestring):
-            try:
-                json_msg = json.loads(str(msg))
-                if isinstance(json_msg, dict):
-                    self._add_dic(data, json_msg)
-                else:
-                    self._add_dic(data, {'message': str(json_msg)})
-            except ValueError:
-                msg = record.getMessage()
-                self._add_dic(data, {'message': msg})
+            self._add_dic(data, self._format_msg(record, msg))
         else:
             self._add_dic(data, {'message': msg})
 
+    def _format_msg_json(self, record, msg):
+        try:
+            json_msg = json.loads(str(msg))
+            if isinstance(json_msg, dict):
+                return json_msg
+            else:
+                return {'message': str(json_msg)}
+        except ValueError:
+            return self._format_msg_default(record, msg)
+
+    def _format_msg_default(self, record, msg):
+        return {'message': record.getMessage()}
+
     @staticmethod
     def _add_dic(data, dic):
         for key, value in dic.items():
@@ -130,6 +143,7 @@ class FluentHandler(logging.Handler):
     '''
     Logging Handler for fluent.
     '''
+
     def __init__(self,
                  tag,
                  host='localhost',

tests/test_handler.py

@@ -165,6 +165,20 @@ def test_json_encoded_message(self):
         self.assertTrue('key' in data[0][2])
         self.assertEqual('hello world!', data[0][2]['key'])
 
+    def test_json_encoded_message_without_json(self):
+        handler = fluent.handler.FluentHandler('app.follow', port=self._port)
+
+        logging.basicConfig(level=logging.INFO)
+        log = logging.getLogger('fluent.test')
+        handler.setFormatter(fluent.handler.FluentRecordFormatter(format_json=False))
+        log.addHandler(handler)
+        log.info('{"key": "hello world!", "param": "value"}')
+        handler.close()
+
+        data = self.get_data()
+        self.assertTrue('key' not in data[0][2])
+        self.assertEqual('{"key": "hello world!", "param": "value"}', data[0][2]['message'])
+
     def test_unstructured_message(self):
         handler = fluent.handler.FluentHandler('app.follow', port=self._port)