ProtobufDeserializer raises ValueError("MessageDescriptor not found in file") with a message type generated by the protocol buffer compiler

[jeff-polston]

Description

Using ProtobufDeserializer with a message type generated by the protocol buffer compiler. Results in a ValueError("MessageDescriptor not found in file"). Was able to reproduce with the protobuf_consumer.py example.

Traceback (most recent call last):
  File "/app/confluent-kafka-python/examples/protobuf_consumer.py", line 90, in <module>
    main(parser.parse_args())
  File "/app/confluent-kafka-python/examples/protobuf_consumer.py", line 44, in main
    protobuf_deserializer = ProtobufDeserializer(user_pb2.User,
  File "/usr/local/lib/python3.10/site-packages/confluent_kafka/schema_registry/protobuf.py", line 496, in __init__
    self._msg_index = _create_msg_index(descriptor)
  File "/usr/local/lib/python3.10/site-packages/confluent_kafka/schema_registry/protobuf.py", line 112, in _create_msg_index
    raise ValueError("MessageDescriptor not found in file")
ValueError: MessageDescriptor not found in file

How to reproduce

Dockerfile to reproduce from protobuf_consumer example.

FROM python:3.10.5-buster as python-base

RUN apt-get update -y
RUN mkdir /app
WORKDIR /app

RUN git clone https://github.com/confluentinc/confluent-kafka-python.git
WORKDIR /app/confluent-kafka-python/examples
RUN pip install -r requirements.txt

CMD ["python", "protobuf_consumer.py", "-b", "localhost", "-s", "any", "-t", "help", "-g", "example"]

Checklist

Please provide the following information:

• [x] confluent-kafka-python and librdkafka version (confluent_kafka.version() and confluent_kafka.libversion()): confluent_kafka.version(): ('1.9.0', 17367040) confluent_kafka.libversion(): ('1.9.0', 17367295)
• [ ] Apache Kafka broker version:
• [x] Client configuration: provided example
• [x] Operating system: Debian
• [x] Provide client logs (with 'debug': '..' as necessary)
• [x] Provide broker log excerpts
• [x] Critical issue