How to add trace_id and span_id to the stdout output?

[nealwei2008]

When use otlp as accesslog's output, I can get trace_id and span_id. And how to add trace_id and span_id to the stdout output?

[zirain]

use %TRACE_ID% for trace id, there's no a simple to for span_id, you need to dump it from header when there's one.

[nealwei2008]

OK. I got the trace_id with %TRACE_ID%.
And about the span_id, I can get it with opentelemetry output with default configuration. I don't know what happend. Maybe because enable the envoy tracing. doc. And how can I log it to stdout?

This is my config file.

apiVersion: gateway.envoyproxy.io/v1alpha1
kind: EnvoyProxy
metadata:
  name: otel-cur
  namespace: envoy-gateway-system
spec:
  telemetry:
    accessLog:
      settings:
        - format:
            type: JSON
            json:
              "start_time": "%START_TIME%"
              "method": "%REQ(:METHOD)%"
...
              "trace_id": "%TRACE_ID%"
          sinks:
            - type: File
              file:
                path: "/dev/stdout"

[zirain]

Actuall there're two span id here, that's the main reason why we didn't have a command like %SPAN_ID%.