func()

in datasource/etcd/ms.go [484:550]
61 lines of code
10 McCabe index (conditional complexity)

func (ds *MetadataManager) GetInstance(ctx context.Context, request *pb.GetOneInstanceRequest) (
	*pb.GetOneInstanceResponse, error) {
	domainProject := util.ParseDomainProject(ctx)

	service := &pb.MicroService{}
	var err error
	if len(request.ConsumerServiceId) > 0 {
		service, err = eutil.GetService(ctx, domainProject, request.ConsumerServiceId)
		if err != nil {
			if errors.Is(err, datasource.ErrNoData) {
				log.Debug(fmt.Sprintf("consumer does not exist in db, consumer[%s] find provider instance[%s/%s]",
					request.ConsumerServiceId, request.ProviderServiceId, request.ProviderInstanceId))
				return nil, pb.NewError(pb.ErrServiceNotExists,
					fmt.Sprintf("Consumer[%s] does not exist.", request.ConsumerServiceId))
			}
			log.Error(fmt.Sprintf("get consumer failed, consumer[%s] find provider instance[%s/%s]",
				request.ConsumerServiceId, request.ProviderServiceId, request.ProviderInstanceId), err)
			return nil, pb.NewError(pb.ErrInternal, err.Error())
		}
	}

	provider, err := eutil.GetService(ctx, domainProject, request.ProviderServiceId)
	if err != nil {
		if errors.Is(err, datasource.ErrNoData) {
			log.Debug(fmt.Sprintf("provider does not exist in db, consumer[%s] find provider instance[%s/%s]",
				request.ConsumerServiceId, request.ProviderServiceId, request.ProviderInstanceId))
			return nil, pb.NewError(pb.ErrServiceNotExists,
				fmt.Sprintf("Provider[%s] does not exist.", request.ProviderServiceId))
		}
		log.Error(fmt.Sprintf("get provider failed, consumer[%s] find provider instance[%s/%s]",
			request.ConsumerServiceId, request.ProviderServiceId, request.ProviderInstanceId), err)
		return nil, pb.NewError(pb.ErrInternal, err.Error())
	}

	findFlag := func() string {
		return fmt.Sprintf("Consumer[%s][%s/%s/%s/%s] find provider[%s][%s/%s/%s/%s] instance[%s]",
			request.ConsumerServiceId, service.Environment, service.AppId, service.ServiceName, service.Version,
			provider.ServiceId, provider.Environment, provider.AppId, provider.ServiceName, provider.Version,
			request.ProviderInstanceId)
	}

	var item *cache.VersionRuleCacheItem
	rev, _ := ctx.Value(util.CtxRequestRevision).(string)
	item, err = cache.FindInstances.GetWithProviderID(ctx, service, pb.MicroServiceToKey(domainProject, provider),
		&pb.HeartbeatSetElement{
			ServiceId: request.ProviderServiceId, InstanceId: request.ProviderInstanceId,
		}, request.Tags, rev)
	if err != nil {
		log.Error(fmt.Sprintf("find Instances by providerID failed, %s failed", findFlag()), err)
		return nil, pb.NewError(pb.ErrInternal, err.Error())
	}
	if item == nil || len(item.Instances) == 0 {
		mes := fmt.Errorf("%s failed, provider instance does not exist", findFlag())
		log.Error("find Instances by ProviderID failed", mes)
		return nil, pb.NewError(pb.ErrInstanceNotExists, mes.Error())
	}

	instance := item.Instances[0]
	if rev == item.Rev {
		instance = nil // for gRPC
	}
	_ = util.WithResponseRev(ctx, item.Rev)

	return &pb.GetOneInstanceResponse{
		Instance: instance,
	}, nil
}