PynamoDB patcher bug fix (#72)

* Fixed a pynamodb patcher encoding bug under python3.4 and 3.5

* 1.1.2 release commit

Author: haotianw465

CHANGELOG.rst

@@ -2,6 +2,10 @@
 CHANGELOG
 =========
 
+1.1.2
+=====
+* bugfix: Fixed an issue on PynamoDB patcher where the capture didn't handle client timeout.
+
 1.1.1
 =====
 * bugfix: Handle Aiohttp Exceptions as valid responses `PR59 <https://github.com/aws/aws-xray-sdk-python/pull/59>`_.

aws_xray_sdk/ext/pynamodb/patch.py

@@ -42,22 +42,24 @@ def pynamodb_meta_processor(wrapped, instance, args, kwargs, return_value,
                             exception, subsegment, stack):
     operation_name = args[0].headers['X-Amz-Target'].decode('utf-8').split('.')[1]
     region = args[0].url.split('.')[1]
-    request_id = return_value.headers.get('x-amzn-RequestId')
 
     aws_meta = {
         'operation': operation_name,
-        'request_id': request_id,
         'region': region
     }
 
+    # in case of client timeout the return value will be empty
+    if return_value is not None:
+        aws_meta['request_id'] = return_value.headers.get('x-amzn-RequestId')
+        subsegment.put_http_meta(http.STATUS, return_value.status_code)
+
     if exception:
         subsegment.add_error_flag()
         subsegment.add_exception(exception, stack, True)
 
-    subsegment.put_http_meta(http.STATUS, return_value.status_code)
-
+    resp = return_value.json() if return_value else None
     _extract_whitelisted_params(subsegment.name, operation_name, aws_meta,
                                 [None, json.loads(args[0].body.decode('utf-8'))],
-                                None, return_value.json())
+                                None, resp)
 
     subsegment.set_aws(aws_meta)

aws_xray_sdk/version.py

@@ -1 +1 @@
-VERSION = '1.1.1'
+VERSION = '1.1.2'

tests/ext/pynamodb/test_pynamodb.py

@@ -54,6 +54,29 @@ class Meta:
     assert aws_meta['table_name'] == 'mytable'
 
 
+def test_empty_response():
+    from aws_xray_sdk.ext.pynamodb.patch import pynamodb_meta_processor
+    subsegment = xray_recorder.begin_subsegment('test')
+
+    class TempReq(object):
+        def __init__(self):
+            self.headers = {'X-Amz-Target': 'ddb.ListTables'.encode('utf-8')}
+            self.url = 'ddb.us-west-2'
+            self.body = '{}'.encode('utf-8')
+
+    prepared_request = TempReq()
+    args = [prepared_request]
+
+    pynamodb_meta_processor(wrapped=None, instance=None, args=args,
+                            kwargs=None, return_value=None,
+                            exception=None, subsegment=subsegment,
+                            stack=None)
+
+    aws_meta = subsegment.aws
+    assert aws_meta['region'] == 'us-west-2'
+    assert aws_meta['operation'] == 'ListTables'
+
+
 def test_only_dynamodb_calls_are_traced():
     """Test only a single subsegment is created for other AWS services.