fix: Invalid type in attribute sequence when using sessions

fixes open-telemetry#1918
closes open-telemetry#2010

Author: smoke

instrumentation/opentelemetry-instrumentation-pymongo/src/opentelemetry/instrumentation/pymongo/__init__.py

@@ -152,7 +152,7 @@ def started(self, event: monitoring.CommandStartedEvent):
                         SpanAttributes.DB_STATEMENT,
                         _get_statement(event),
                     )
-                if collection:
+                if collection and isinstance(collection, str):
                     span.set_attribute(
                         SpanAttributes.DB_MONGODB_COLLECTION, collection
                     )
@@ -219,7 +219,7 @@ def _get_span_name(event: CommandEvent) -> str:
     """Get the span name for a given pymongo event."""
     command_name = event.command_name
     collection = event.command.get(command_name)
-    if collection:
+    if collection and isinstance(collection, str):
         return f"{event.database_name}.{collection}.{command_name}"
     return f"{event.database_name}.{command_name}"
 

instrumentation/opentelemetry-instrumentation-pymongo/tests/test_pymongo.py

@@ -287,6 +287,31 @@ def test_capture_statement_disabled_aggregate(self):
 
         self.assertNotIn(SpanAttributes.DB_STATEMENT, span.attributes)
 
+    def test_endsessions_command_with_dict_list_collection(self):
+        # Test for https://github.com/open-telemetry/opentelemetry-python-contrib/issues/1918
+        # endSessions command has a list of dictionaries as collection value
+        command_attrs = {
+            "command_name": "endSessions",
+            "endSessions": [
+                {"id": {"id": "session1"}},
+                {"id": {"id": "session2"}},
+            ],
+        }
+        command_tracer = CommandTracer(self.tracer)
+        mock_event = MockEvent(command_attrs)
+        command_tracer.started(event=mock_event)
+        command_tracer.succeeded(event=mock_event)
+
+        spans_list = self.memory_exporter.get_finished_spans()
+        self.assertEqual(len(spans_list), 1)
+        span = spans_list[0]
+
+        # Should not have DB_MONGODB_COLLECTION attribute since collection is not a string
+        self.assertNotIn(SpanAttributes.DB_MONGODB_COLLECTION, span.attributes)
+        self.assertEqual(span.attributes[SpanAttributes.DB_OPERATION], "endSessions")
+        # Span name should not include collection name
+        self.assertEqual(span.name, "database_name.endSessions")
+
 
 class MockCommand:
     def __init__(self, command_attrs):

tests/opentelemetry-docker-tests/tests/pymongo/test_pymongo_functional.py

@@ -163,3 +163,34 @@ def test_uninstrument(self):
         self._collection.find_one()
         spans = self.memory_exporter.get_finished_spans()
         self.assertEqual(len(spans), 1)
+
+    def test_session_end_no_error(self):
+        """Test that endSessions doesn't cause instrumentation errors (issue #1918)"""
+        client = MongoClient(
+            MONGODB_HOST, MONGODB_PORT, serverSelectionTimeoutMS=2000
+        )
+        
+        with self._tracer.start_as_current_span("rootSpan"):
+            session = client.start_session()
+            db = client[MONGODB_DB_NAME]
+            collection = db[MONGODB_COLLECTION_NAME]
+            # Do a simple operation within the session
+            collection.find_one({"test": "123"})
+            # End the session - this should not cause an error
+            session.end_session()
+        
+        # Verify spans were created without errors  
+        spans = self.memory_exporter.get_finished_spans()
+        # Should have at least the find and endSessions operations
+        self.assertGreaterEqual(len(spans), 2)
+        
+        session_end_spans = [s for s in spans if s.attributes.get(SpanAttributes.DB_OPERATION) == "endSessions"]
+        if session_end_spans:
+            span = session_end_spans[0]
+            # Should not have DB_MONGODB_COLLECTION attribute since endSessions collection is not a string
+            self.assertNotIn(SpanAttributes.DB_MONGODB_COLLECTION, span.attributes)
+            # Should have other expected attributes
+            self.assertEqual(span.attributes[SpanAttributes.DB_OPERATION], "endSessions")
+            self.assertEqual(span.attributes[SpanAttributes.DB_NAME], MONGODB_DB_NAME)
+        
+        client.close()