[aws] Blacklist arguments stored as tags (#761)

* Add blacklist for params argument of function

* Remove unnecessary import

* Add blacklist to aiobotocore

* Check params

* Fix tests

* Add blacklisted for s3

* Remove commented-out line

Author: majorgreys

ddtrace/ext/aws.py

@@ -1,7 +1,10 @@
 from ..utils.formats import flatten_dict
 
 
-BLACKLIST_ENDPOINT = ["kms", "sts"]
+BLACKLIST_ENDPOINT = ['kms', 'sts']
+BLACKLIST_ENDPOINT_TAGS = {
+    's3': ['params.Body'],
+}
 
 
 def truncate_arg_value(value, max_len=1024):
@@ -16,13 +19,18 @@ def truncate_arg_value(value, max_len=1024):
 
 def add_span_arg_tags(span, endpoint_name, args, args_names, args_traced):
     if endpoint_name not in BLACKLIST_ENDPOINT:
+        blacklisted = BLACKLIST_ENDPOINT_TAGS.get(endpoint_name, [])
         tags = dict(
             (name, value)
             for (name, value) in zip(args_names, args)
             if name in args_traced
         )
         tags = flatten_dict(tags)
-        tags = {k: truncate_arg_value(v) for k, v in tags.items()}
+        tags = {
+            k: truncate_arg_value(v)
+            for k, v in tags.items()
+            if k not in blacklisted
+        }
         span.set_tags(tags)
 
 

tests/contrib/aiobotocore/test.py

@@ -80,7 +80,7 @@ def test_s3_put(self):
         self.assertEqual(spans[1].resource, 's3.putobject')
         self.assertEqual(spans[1].get_tag('params.Key'), stringify(params['Key']))
         self.assertEqual(spans[1].get_tag('params.Bucket'), stringify(params['Bucket']))
-        self.assertEqual(spans[1].get_tag('params.Body'), stringify(params['Body']))
+        self.assertIsNone(spans[1].get_tag('params.Body'))
 
     @mark_asyncio
     def test_s3_client_error(self):

tests/contrib/botocore/test.py

@@ -1,5 +1,5 @@
 # stdlib
-import unittest
+from unittest import TestCase
 
 # 3p
 import botocore.session
@@ -16,7 +16,7 @@
 from ...test_tracer import get_dummy_tracer
 
 
-class BotocoreTest(unittest.TestCase):
+class BotocoreTest(TestCase):
     """Botocore integration testsuite"""
 
     TEST_SERVICE = "test-botocore-tracing"
@@ -104,7 +104,8 @@ def test_s3_put(self):
         self.assertEqual(spans[1].resource, 's3.putobject')
         self.assertEqual(spans[1].get_tag('params.Key'), stringify(params['Key']))
         self.assertEqual(spans[1].get_tag('params.Bucket'), stringify(params['Bucket']))
-        self.assertEqual(spans[1].get_tag('params.Body'), stringify(params['Body']))
+        # confirm blacklisted
+        self.assertIsNone(spans[1].get_tag('params.Body'))
 
     @mock_sqs
     def test_sqs_client(self):