Incorrect Protocol Buffer Deserialization/Marshaling In Spring AMQP

I am trying to figure out why my protocol buffer payload is being incorrectly de-serialized when received from a Spring AMQP listener in my Java app. The protocol buffer is written in a Go service and sent to a Rabbit MQ instance which is then picked up by the Java Spring app and de-serialized into an object instance.

For some reason when received the marshalled object has field 2 with the value of field 1 while field 1 is null in the resulting object. Additionally the repeated network_interfaces field with key 5 is null on the object.

Interestingly if I use the debugger when picking up a message from the queue, the missing fields are visible and contain the correct data on the instantiated protobuf object under unknownFields so it looks like a case of the proto parser not working correctly. The debugger shows that the field keys are off, i.e. field 1 has the key 2 and so on.

So far I have:

• Verified the proto files are the same in both services, the Spring app is using the proto file from the other repo by importing it as a git submodule
• Attempted to use a Spring.messaging.amqp MessageConverter to deserialize the proto explicitly based on message headers with no success
• Tried different message content type and encoding headers when sending the message, these don't appear to make a difference as I am only using the message body.
• Verified that if the Go app listens to the queue that it can deserialize and unmarshal a message it sent correctly, so this has to be a Spring config issue or similar.

The Proto3 message definition in question:

message HostStateMessage {

  message NetworkInterface {
    string name = 1;
    string mac_address = 2;
    string ipv4 = 3;
    string ipv6 = 4;
  }

  string hostname = 1;
  string description = 2;
  HostType host_type = 3;
  repeated NetworkInterface network_interfaces = 4;
}

The Go function which writes the protocol buffer to RabbitMQ as a message:

func PublishHostMessage(config *AMQPQueueConfiguration, conn *amqp.Connection, message *protos.HostStateMessage) error {
    channel, err := conn.Channel()
    if err != nil {
        fmt.Errorf("Creating channel failed: %s\n", err)
        return err
    }

    queue, err := channel.QueueDeclare(config.HostQueueName, true, false, false, false, nil)
    if err != nil {
        fmt.Errorf("Failed to declare queue: %s\n", err)
        return err
    }

    serialMsg, err := proto.Marshal(message)
    if err != nil {
        fmt.Errorf("Failed to serialize proto message: %s\n", err)
        return err
    }
    headers := amqp.Table{}
    headers["messageType"] = "HostStateMessage"
    fmt.Println(string(serialMsg))
    err = channel.Publish("", queue.Name, false, false, amqp.Publishing{Headers: headers, ContentType: "application/x-protobuf", Body: serialMsg})
    if err != nil {
        fmt.Errorf("Failed to send message: %s\n", err)
        return err
    }

    fmt.Printf("Sent host message at: %s\n", time.Now())
    return nil
}

The MessageReceiver.java Class:

@Service
public class MessageReceiver {

  @Autowired RabbitConfiguration rabbitConfiguration;
  @Autowired HostDao hostDao;

  @RabbitListener(queues = "#{rabbitConfiguration.hostQueueName}")
  public void consumeHostNotification(Message in) {
    try {
      HostStateMessage message = HostStateMessage.parseFrom(in.getBody());
      hostDao.addOrUpdateHostStateFromMessage(message);
    } catch (InvalidProtocolBufferException e) {
      System.out.println(e.getStackTrace());
    }
  }
}

The Spring AMQP @Configuration bean:

@Configuration
@EnableAutoConfiguration
public class RabbitConfiguration {

  @Value("${rabbitmq.hostname}")
  private String queueHost;

  @Value("${rabbitmq.port}")
  private int queuePort;

  @Value("${rabbitmq.queues.host-queue-name}")
  public String hostQueueName;

  @Bean
  public CachingConnectionFactory connectionFactory() {
    return new CachingConnectionFactory(queueHost, queuePort);
  }

  @Bean
  public Queue hostNotificationQueue() {
    return new Queue(hostQueueName);
  }
}

Go is using google.golang.org/protobuf v1.27.1 in Go modules.

Java is using com.google.protobuf 3.19.4 as a Maven dependency. Along with protobuf-maven-plugin 0.6.1 to do the compilation with protoc.

This is a really confusing issue, would be great to get some insight.