GCP logging does not include span and sampled fields in structured logging

[wabrit]

I'm using version 2.11.0 of the quarkus-google-cloud-logging quarkiverse extension so that I can include tracing information when logging to GCP.

Following the instructions here I've implemented a TraceInfoExtractor that returns the current trace and span ids.

However the resulting payload, while it includes the trace in the format GCP expects, does not include the logging.googleapis.com/spanId value, and logging.googleapis.com/trace_sampled is left defaulted to false.

{
    "severity":"WARNING",
    "time":"2024-09-18T10:31:19.270162900Z",
    "logging.googleapis.com/labels":{},
    "logging.googleapis.com/trace":"projects/myProject/traces/2e6d1e217fe2a1c2c331424649918107",
    "logging.googleapis.com/trace_sampled":false,
       ...
}

Without these additional fields, it is not possible to navigate between traces and logs in the GCP console.

As far as I can see the issue is in the LoggingHandler#transform method from this extension, which omits to call the builder methods to set these (see java comments):

private LogEntry transform(ExtLogRecord record, TraceInfo trace) {
        Payload<?> payload = internalHandler.transform(record, trace);
        if (payload != null) {
            com.google.cloud.logging.LogEntry.Builder builder = LogEntry.newBuilder(payload)
                    .setSeverity(LevelTransformer.toSeverity(record.getLevel()))
                    .setTimestamp(record.getInstant());

           /*
            * Ideally should be setting labels for logging here too i.e.
            *
            * builder.addLabel("levelName", LevelTransformer.toSeverity(record.getLevel()).toString())
            * builder.addLabel("levelValue", String.valueOf(level.intValue()))
            * builder.addLabel("loggerName", extLogRecord.getSourceClassName())
            */ 

            if (this.config.gcpTracing().enabled() && trace != null && !Strings.isNullOrEmpty(trace.getTraceId())) {
                builder = builder.setTrace(composeTraceString(trace.getTraceId()));

               /* Should also be setting these for integrated log/tracing support:
                 *  builder.setSpan(trace.getSpanId())
                 *  builder.setTraceSampled(true) 
                 */
            }
            return builder.build();
        } else {
            return null;
        }
    }