func (c *vesselServiceClient) FindAvailable(ctx context.Context, in *Specification, opts ...client.CallOption) (*Response, error) {
	req := c.c.NewRequest(c.serviceName, "VesselService.FindAvailable", in)
	out := new(Response)
	err := c.c.Call(ctx, req, out, opts...)
	if err != nil {
		return nil, err
	}
	return out, nil
}

// 直接调用自己写的公有的库获取 server，保持配置同步	
// common.AuthWrapper 为前置认证，采用JWT
srv := common.GetMicroServer(service, micro.WrapHandler(common.AuthWrapper))

func GetMicroServer(service string, exOpts ...micro.Option) micro.Service {
	opts := getOpts(service)
	if defaultServer != nil {
		opts = append(opts, defaultServer)
	}
	// ...
    
    // 注意顺序，同样的配置后面的会将前面的覆盖
	opts = append(opts, exOpts...)

	srv := micro.NewService(opts...)
	// 初始化，解析命令行参数
	srv.Init()
	return srv
}

// 注册延迟，30s 内没有注册则失效，consul 会自动删除服务
        micro.RegisterTTL(time.Second * 30),
// 注册间隔，每隔 20s 注册一次
		micro.RegisterInterval(time.Second * 20)
// ...
// opts 中添加如下配置即可
micro.Registry(consul.NewRegistry(func(op *registry.Options) {
			op.Addrs = config.GetRegistryAddrs(service)
		}))

	// 这里的 handler 应当实现 pb 中定义的调用
    h := handler.GetHandler(session, vClient, uClient, bk)	
    // 将 server 作为微服务的服务端
	pb.RegisterShippingServiceHandler(srv.Server(), h)

	if err := srv.Run(); err != nil {
		log.Fatalf("failed to serve: %v", err)
	}

func (h *Handler) CreateConsignment(ctx context.Context, req *pb.Consignment, resp *pb.Response) error {
}
func (h *Handler) GetConsignments(ctx context.Context, req *pb.GetRequest, resp *pb.Response) error {
}

//
//  AuthWrapper 是一个高阶函数，入参是 "下一步" 函数，出参是认证函数
// 在返回的函数内部处理完认证逻辑后，再手动调用 fn() 进行下一步处理
// token 是从 上下文中取出的，再调用 user-service 将其做验证
// 认证通过则 fn() 继续执行，否则报错
//
func AuthWrapper(fn server.HandlerFunc) server.HandlerFunc {
	log.Println("AuthWrapper")
	return func(ctx context.Context, req server.Request, resp interface{}) error {
		// consignment-service 独立测试时不进行认证
		if os.Getenv("DISABLE_AUTH") == "true" {
			return fn(ctx, req, resp)
		}
		meta, ok := metadata.FromContext(ctx)
		if !ok {
			return errors.New("no auth meta-data found in request")
		}

		token := meta["token"]

		// Auth here
		authResp, err := GetUserClient().ValidateToken(context.Background(), &userPb.Token{
			Token: token,
		})

		log.Println("Auth Resp:", authResp)
		if err != nil {
			return err
		}
        // 这里将 JWT 解析出来的 user_id 传递下去
		ctx = context.WithValue(ctx, "user_id", authResp.UserId)
		err = fn(ctx, req, resp)
		return err
	}
}

func (h *Handler) CreateConsignment(ctx context.Context, req *pb.Consignment, resp *pb.Response) error {
    // ... 处理
	resp.Created = true
	resp.Consignment = req

    // 后置操作
	go func() {
		// ...
		h.pubLog(userID, "CreateConsignment", msg)
	}()
	return nil
}

// Filter will filter the version of the service
func Filter(v string) client.CallOption {
	if v == "" {
		v = "latest"
	}
	filter := func(services []*registry.Service) []*registry.Service {
		var filtered []*registry.Service

		for _, service := range services {
			if service.Version == v {
				filtered = append(filtered, service)
			}
		}

		return filtered
	}

	return client.WithSelectOption(selector.WithFilter(filter))
}

vResp, err := h.vesselClient.FindAvailable(ctx, vReq, common.Filter(version))

func (repo *ConsignmentRepository) Create(con *pb.Consignment) error {
    // 这里将PB转换为想要的结构体，之后再插入
	data := PBConsignment2Consignment(con)
    // dao 层直接对接DB操作
	return dao.Insert(repo.collection(), &data)
}

// 在外面记得把 Session Close

// common/service.go/GetMicroServer()
// 注册
    brokerKafka := kafka.NewBroker(func(options *broker.Options) {
        // eg: []{"127.0.0.1:9092"}
		options.Addrs = config.GetBrokerAddrs(service)
	})
	if err := brokerKafka.Connect(); err != nil {
		log.Fatalf("Broker Connect error: %v", err)
	}
// ... micro.Broker(brokerKafka)

	// 这里我将 kafka broker 传入 handler 中
    bk := srv.Server().Options().Broker
	h := handler.GetHandler(session, vClient, uClient, bk)

// 发送log
   // ...
   data := &broker.Message{
      Header: map[string]string{
         "user_id": userID,
      },
      Body: body,
   }

   if err := h.Broker.Publish(topic, data); err != nil {
      log.Printf("[pub] failed: %v\n", err)
   }

	bk := srv.Server().Options().Broker
    // 这里订阅了 一个 topic, 并提供接口处理
	_, err := bk.Subscribe(topic, subLog)

func subLog(pub broker.Publication) error {
	var logPB *pb.Log
    // 自行解析 body 即可
	if err := json.Unmarshal(pub.Message().Body, &logPB); err != nil {
		return err
	}
	log.Printf("[Log]: user_id: %s,  Msg: %v\n", pub.Message().Header["user_id"], logPB)
	return nil
}

var (
    // DefaultTimeout is how long to wait for command to complete, in milliseconds
    DefaultTimeout = 1000
    // DefaultMaxConcurrent is how many commands of the same type can run at the same time
    DefaultMaxConcurrent = 10
    // DefaultVolumeThreshold is the minimum number of requests needed before a circuit can be tripped due to health
    DefaultVolumeThreshold = 20
    // DefaultSleepWindow is how long, in milliseconds, to wait after a circuit opens before testing for recovery
    DefaultSleepWindow = 5000
    // DefaultErrorPercentThreshold causes circuits to open once the rolling measure of errors exceeds this percent of requests
    DefaultErrorPercentThreshold = 50
    // DefaultLogger is the default logger that will be used in the Hystrix package. By default prints nothing.
    DefaultLogger = NoopLogger{}
)

type Settings struct {
    Timeout                time.Duration
    MaxConcurrentRequests  int
    RequestVolumeThreshold uint64
    SleepWindow            time.Duration
    ErrorPercentThreshold  int
}

//  "github.com/afex/hystrix-go/hystrix"	
    hystrix.DefaultMaxConcurrent = 100
	hystrix.DefaultVolumeThreshold = 50

// "github.com/micro/go-plugins/wrapper/breaker/hystrix"
// 添加如下配置即可
micro.WrapClient(hystrix.NewClientWrapper()

// "github.com/micro/go-plugins/wrapper/ratelimiter/uber"
// 添加如下配置即可
// ratelimit 的配置可自行查看 API 修改
micro.WrapClient(ratelimit.NewHandlerWrapper(1024))

func NewJaegerTracer(serviceName, addr string) (opentracing.Tracer, io.Closer, error) {
	// Sample configuration for testing. Use constant sampling to sample every trace
	// and enable LogSpan to log every span via configured Logger.
	cfg := jaegercfg.Configuration{
		Sampler: &jaegercfg.SamplerConfig{
			Type:  jaeger.SamplerTypeConst,
			Param: 1,
		},
		Reporter: &jaegercfg.ReporterConfig{
			LogSpans: true,
			BufferFlushInterval: 1 * time.Second,
		},
	}

	cfg.ServiceName = serviceName

	// Example logger and metrics factory. Use github.com/uber/jaeger-client-go/log
	// and github.com/uber/jaeger-lib/metrics respectively to bind to real logging and metrics
	// frameworks.
	jLogger := &jaegerLogger{}
	jMetricsFactory := metrics.NullFactory

	metricsFactory := metrics.NullFactory
	metrics := jaeger.NewMetrics(metricsFactory, nil)

	sender, err := jaeger.NewUDPTransport(addr, 0)
	if err != nil {
		log.Logf("could not initialize jaeger sender: %s", err.Error())
		return nil, nil, err
	}

	repoter := jaeger.NewRemoteReporter(sender, jaeger.ReporterOptions.Metrics(metrics))

	return cfg.NewTracer(
		jaegercfg.Logger(jLogger),
		jaegercfg.Metrics(jMetricsFactory),
		jaegercfg.Reporter(repoter),
	)

}

type jaegerLogger struct{}

func (l *jaegerLogger) Error(msg string) {
	log.Logf("ERROR: %s", msg)
}

// Infof logs a message at info priority
func (l *jaegerLogger) Infof(msg string, args ...interface{}) {
	log.Logf(msg, args...)
}

// 	"github.com/micro/go-plugins/wrapper/trace/opentracing"
opentracing.NewClientWrapper(t)

	// web 的初始化不太一样 micro -> web
    srv := common.GetMicroWeb(service)
    // ...
    router := gin.Default()
    // ... 正常 gin router 绑定操作
    // 最后直接将 服务 / 绑定到 gin 的router上，交给 gin 处理
	srv.Handle("/", router)