大致代码(Gin 部分)如下，不知道是不是我哪里理解或者使用方式不当？

之前链路追踪实践的经验比较少，如果有什么小白的地方作者还望大大多多包涵（抱拳）。

// main.go

var (
	tracerCloser io.Closer
)

func main() {
        // 调用 tracer 初始化
	tracerCloser = initialize.InitGlobalTracer()
        // 调用 gin 初始化
	core.RunServer()
	err := tracerCloser.Close()
	if err != nil {
		fmt.Println("tracerCloser failed:", err.Error())
	}
}

//  initialize.jaeger.go
package initialize

import (
	"io"

	"github.com/opentracing/opentracing-go"
	"github.com/temptup/temptup.api/global"
	"github.com/uber/jaeger-client-go"
	"github.com/uber/jaeger-client-go/transport"
)

func initJaeger(service, url string) (opentracing.Tracer, io.Closer) {
	sender := transport.NewHTTPTransport(url)
	reporter := jaeger.NewRemoteReporter(sender, jaeger.ReporterOptions.Logger(jaeger.StdLogger))

	// samples 100% of traces
	tracer, closer := jaeger.NewTracer(service, jaeger.NewConstSampler(true), reporter)
	return tracer, closer
}

func InitGlobalTracer() io.Closer {
	// the closer can be used in shutdown hooks
	tracer, closer := initJaeger("demo", "http://127.0.0.1")

	opentracing.SetGlobalTracer(tracer)
	return closer
}

// core.server.go
func RunServer() {
    router := initialize.Routers()

    s := initServer("127.0.0.1:8888", router)

    go func() {
        fmt.Println(s.ListenAndServe().Error())
    }()

    graceful.ShutdownAndCleanup(func() {
        _, cancel := context.WithTimeout(context.Background(), 5*time.Second)
        cancel()
    })
}

// initialize.router.go
var Router = gin.Default()

// jaeger
func Routers() *gin.Engine {

    var Router = gin.Default()

    // 注入 trace
    Router.Use(otgin.NewMiddleware(Router))

    // swagger
    Router.GET("/swagger/*any", ginSwagger.WrapHandler(swaggerFiles.Handler))
    // ......
    fmt.Println("register swagger handler")

    return Router
}