fix: Pymongo raises an AttributeError when the tracer is disabled (#3157) (#3169)

Currently we attempt to wrap pymongo operations in a span when tracer.enabled == False. This raises an exception since spans are not generated on a disabled tracer. An example of this error is linked below:

Fix: #3140
(cherry picked from commit af5784e)

Co-authored-by: Munir Abdinur <[email protected]>

Author: mergify[bot]

ddtrace/contrib/pymongo/client.py

@@ -121,7 +121,10 @@ def _datadog_trace_operation(self, operation):
     if VERSION >= (3, 12, 0):
 
         def run_operation(self, sock_info, operation, *args, **kwargs):
-            with self._datadog_trace_operation(operation) as span:
+            span = self._datadog_trace_operation(operation)
+            if span is None:
+                return self.__wrapped__.run_operation(sock_info, operation, *args, **kwargs)
+            with span:
                 result = self.__wrapped__.run_operation(sock_info, operation, *args, **kwargs)
                 if result and result.address:
                     set_address_tags(span, result.address)
@@ -131,7 +134,10 @@ def run_operation(self, sock_info, operation, *args, **kwargs):
     elif (3, 9, 0) <= VERSION < (3, 12, 0):
 
         def run_operation_with_response(self, sock_info, operation, *args, **kwargs):
-            with self._datadog_trace_operation(operation) as span:
+            span = self._datadog_trace_operation(operation)
+            if span is None:
+                return self.__wrapped__.run_operation_with_response(sock_info, operation, *args, **kwargs)
+            with span:
                 result = self.__wrapped__.run_operation_with_response(sock_info, operation, *args, **kwargs)
                 if result and result.address:
                     set_address_tags(span, result.address)
@@ -141,7 +147,10 @@ def run_operation_with_response(self, sock_info, operation, *args, **kwargs):
     else:
 
         def send_message_with_response(self, operation, *args, **kwargs):
-            with self._datadog_trace_operation(operation) as span:
+            span = self._datadog_trace_operation(operation)
+            if span is None:
+                return self.__wrapped__.send_message_with_response(operation, *args, **kwargs)
+            with span:
                 result = self.__wrapped__.send_message_with_response(operation, *args, **kwargs)
                 if result and result.address:
                     set_address_tags(span, result.address)

releasenotes/notes/pymongo-disabled-tracer-bug-fix-d7782296afe5c1a9.yaml

@@ -0,0 +1,3 @@
+fixes:
+  - |
+    Pymongo instrumentation raises an AttributeError when ``tracer.enabled == False``

tests/contrib/pymongo/test.py

@@ -484,6 +484,64 @@ def test_user_specified_service(self):
         assert len(spans) == 1
         assert spans[0].service != "mysvc"
 
+    def test_patch_with_disabled_tracer(self):
+        tracer, client = self.get_tracer_and_client()
+        tracer.configure(enabled=False)
+
+        db = client.testdb
+        db.drop_collection("teams")
+        teams = [
+            {
+                "name": "Toronto Maple Leafs",
+                "established": 1917,
+            },
+            {
+                "name": "Montreal Canadiens",
+                "established": 1910,
+            },
+            {
+                "name": "New York Rangers",
+                "established": 1926,
+            },
+            {
+                "name": "Boston Knuckleheads",
+                "established": 1998,
+            },
+        ]
+
+        # create records (exercising both ways of inserting)
+        db.teams.insert_one(teams[0])
+        db.teams.insert_many(teams[1:])
+        # delete record
+        db.teams.delete_one({"name": "Boston Knuckleheads"})
+
+        # assert one team was deleted
+        cursor = db["teams"].find()
+        count = 0
+        for row in cursor:
+            count += 1
+        assert count == len(teams) - 1
+
+        # query record
+        q = {"name": "Toronto Maple Leafs"}
+        queried = list(db.teams.find(q))
+        assert len(queried) == 1
+        assert queried[0]["name"] == "Toronto Maple Leafs"
+        assert queried[0]["established"] == 1917
+
+        # update record
+        result = db.teams.update_many(
+            {"name": "Toronto Maple Leafs"},
+            {"$set": {"established": 2021}},
+        )
+        assert result.matched_count == 1
+        queried = list(db.teams.find(q))
+        assert queried[0]["name"] == "Toronto Maple Leafs"
+        assert queried[0]["established"] == 2021
+
+        # assert no spans were created
+        assert tracer.pop() == []
+
 
 class TestPymongoSocketTracing(TracerTestCase):
     """