For string body make sure we serialize unicode properly

elasticsearch/serializer.py

@@ -21,7 +21,11 @@ class JSONSerializer(object):
     def dumps(self, data):
         # don't serialize strings
         if isinstance(data, (type(''), type(u''))):
-            return data
+            try:
+                return data.encode('utf-8')
+            except UnicodeDecodeError:
+                # Python 2 and str, no need to re-encode
+                return data
 
         try:
             return json.dumps(data, default=self.default)