OpenTelemetry trace context not transmitted when using rawPayload with Kafka

[KarstenWintermann]

In what area(s)?

/area runtime

/area operator

/area placement

/area docs

/area test-and-release

What version of Dapr?

1.12.3

1.1.x
1.0.x
edge: output of git describe --dirty

Expected Behavior

I subscribe to Kafka topics with raw data (i.e. not CloudEvents) and expect to receive the OpenTelemetry trace context which is present in the Kafka header field "traceparent" in the corresponding http header field "traceparent".

Actual Behavior

The header field traceparent is received, but with all zeroes ("00-00000000000000000000000000000000-0000000000000000-00"). The same operation is successful when using CloudEvents.

This behavior prevents me from passing the OTel trace context between components.

Steps to Reproduce the Problem

The easiest way to reproduce is using the pubsub/java/http quickstart example.

In the checkout component, replace the line

.uri(URI.create(uri))

with

.uri(URI.create(uri + "?metadata.rawPayload=true&metadata.traceparent=00-555d5c767990a1d9029cfafb9884a7ab-dc66cf5a8aa8c6d2-01"))
(The value for "traceparent" is just a random example, which in reality would be created by the OTel runtime.)

Then add code to the order processing component which outputs the http headers:

    public ResponseEntity<?> processOrders(@RequestBody Order body, @RequestHeader Map<String, String> headers) {
        logger.info("Subscriber received: "+ body.getOrderId());
        headers.forEach((key, value) -> {
            logger.info(String.format("Header '%s' = %s", key, value));
        });

        return ResponseEntity.ok().build();
    }

The output shows that "traceparent" is received as zeroes ("00-00000000000000000000000000000000-0000000000000000-00") while other Kafka header fields like "rawPayload" are passed as http headers unmodified.

Release Note

RELEASE NOTE: FIX OpenTelemetry trace context passed correctly when using rawPayload with Kafka