code with decorator

openebs-provisioner.go

// logic with decorator
// logging functions are exported from github.com/opentracing/opentracing-go/log
func Objdecorator(f func(key string, obj interface{}) log.Field) func(string, interface{}) log.Field {
	return func(key string, obj interface{}) log.Field {
		return log.Object(key, obj)
	}
}

func Strdecorator(f func(key, val string) log.Field) func(string, string) log.Field {
	return func(key, value string) log.Field {
		return log.String(key, value)
	}
}

// NewOpenEBSProvisioner creates a new openebs provisioner
func NewOpenEBSProvisioner(client kubernetes.Interface) controller.Provisioner {
	tracer := tracing.Init("provisioner")
	opentracing.SetGlobalTracer(tracer)
	span := tracer.StartSpan("Return OpenEBS Provisioner instance")

	ctx := opentracing.ContextWithSpan(context.Background(), span)
	defer span.Finish()
	nodeName := os.Getenv("NODE_NAME")
	if nodeName == "" {
		span.LogFields(
      Strdecorator(log.String)("event", "Getenv"),
			log.Error(fmt.Errorf("ENV variable NODE_NAME not set NODE_NAME : %v", nodeName)),
		)
		glog.Errorf("ENV variable 'NODE_NAME' is not set")
	}
	var openebsObj mApiv1.OpenEBSVolume
	span.LogFields(
		Strdecorator(log.String)("event", "get node name"),
		Strdecorator(log.String)("NODE_NAME", nodeName),
	)
	//Get maya-apiserver IP address from cluster
	addr, err := openebsObj.GetMayaClusterIP(ctx, client)

	if err != nil {
		span.LogFields(
      Strdecorator(log.String)("event", "get maya cluster IP"),
			log.Error(err),
		)
		glog.Errorf("Error getting maya-apiserver IP Address: %v", err)
		return nil
	}

	mayaServiceURI := "http://" + addr + ":5656"
	span.LogFields(
		Strdecorator(log.Object)("event", "get maya service URI", "mayaServiceURI", mayaServiceURI),
	)

	//Set maya-apiserver IP address along with default port
	os.Setenv("MAPI_ADDR", mayaServiceURI)
	return &openEBSProvisioner{
		mapiURI:  mayaServiceURI,
		identity: nodeName,
		tracer:   tracer,
	}
}

// logic without decorator
// NewOpenEBSProvisioner creates a new openebs provisioner
func NewOpenEBSProvisioner(client kubernetes.Interface) controller.Provisioner {
	tracer := tracing.Init("provisioner")
	opentracing.SetGlobalTracer(tracer)
	span := tracer.StartSpan("Return OpenEBS Provisioner instance")

	ctx := opentracing.ContextWithSpan(context.Background(), span)
	defer span.Finish()
	nodeName := os.Getenv("NODE_NAME")
	if nodeName == "" {
		span.LogFields(
      log.String("event", "Getenv"),
			log.Error(fmt.Errorf("ENV variable NODE_NAME not set NODE_NAME : %v", nodeName)),
		)
		glog.Errorf("ENV variable 'NODE_NAME' is not set")
	}
	var openebsObj mApiv1.OpenEBSVolume
	span.LogFields(
		log.String("event", "get node name"),
		log.String("NODE_NAME", nodeName),
	)
	//Get maya-apiserver IP address from cluster
	addr, err := openebsObj.GetMayaClusterIP(ctx, client)

	if err != nil {
		span.LogFields(
      log.String("event", "get maya cluster IP"),
			log.Error(err),
		)
		glog.Errorf("Error getting maya-apiserver IP Address: %v", err)
		return nil
	}

	mayaServiceURI := "http://" + addr + ":5656"
	span.LogFields(
		log.Object("event", "get maya service URI", "mayaServiceURI", mayaServiceURI),
	)

	//Set maya-apiserver IP address along with default port
	os.Setenv("MAPI_ADDR", mayaServiceURI)
	return &openEBSProvisioner{
		mapiURI:  mayaServiceURI,
		identity: nodeName,
		tracer:   tracer,
	}
}