[Question] trace.id is not passed about kratos HOT 5 CLOSED

package main

import (
	"context"
	"fmt"
	"os"

	"github.com/gin-gonic/gin"
	kgin "github.com/go-kratos/gin"
	"github.com/go-kratos/kratos/v2"
	"github.com/go-kratos/kratos/v2/errors"
	"github.com/go-kratos/kratos/v2/log"
	"github.com/go-kratos/kratos/v2/middleware"
	"github.com/go-kratos/kratos/v2/middleware/logging"
	"github.com/go-kratos/kratos/v2/middleware/recovery"
	"github.com/go-kratos/kratos/v2/middleware/tracing"
	"github.com/go-kratos/kratos/v2/transport"
	"github.com/go-kratos/kratos/v2/transport/http"
	"go.opentelemetry.io/otel"
	sdktrace "go.opentelemetry.io/otel/sdk/trace"
)

func customMiddleware(handler middleware.Handler) middleware.Handler {
	return func(ctx context.Context, req interface{}) (reply interface{}, err error) {
		if tr, ok := transport.FromServerContext(ctx); ok {
			fmt.Println("operation:", tr.Operation())
		}

		if c, ok := kgin.FromGinContext(ctx); ok {
			c.Request = c.Request.WithContext(ctx)
		}
		reply, err = handler(ctx, req)
		return
	}
}

func main() {
	router := gin.Default()

	tp := sdktrace.NewTracerProvider()
	otel.SetTracerProvider(tp)

	logger := log.With(log.NewStdLogger(os.Stdout),
		"ts", log.DefaultTimestamp,
		"caller", log.DefaultCaller,
		"trace.id", tracing.TraceID(),
		"span.id", tracing.SpanID(),
	)
	log.SetLogger(logger)

	// 使用kratos中间件
	router.Use(kgin.Middlewares(recovery.Recovery(), tracing.Server(), logging.Server(logger), customMiddleware))

	router.GET("/helloworld/:name", func(ctx *gin.Context) {
		name := ctx.Param("name")
		log.Context(ctx.Request.Context()).Info("hello world")
		if name == "error" {
			// 返回kratos error
			kgin.Error(ctx, errors.Unauthorized("auth_error", "no authentication"))
		} else {
			ctx.JSON(200, map[string]string{"welcome": name})
		}
	})

	httpSrv := http.NewServer(http.Address(":8000"))
	httpSrv.HandlePrefix("/", router)

	app := kratos.New(
		kratos.Name("gin"),
		kratos.Logger(logger),
		kratos.Server(
			httpSrv,
		),
	)
	if err := app.Run(); err != nil {
		panic(err)
	}
}