func Start()

in internal/telemetrygen/traces/traces.go [39:114]
65 lines of code
13 McCabe index (conditional complexity)

func Start(cfg *Config) error {
	logger := cfg.Logger
	if logger == nil {
		newLogger, err := common.CreateLogger(cfg.SkipSettingGRPCLogger)
		if err != nil {
			return err
		}
		logger = newLogger
	}

	var exp *otlptrace.Exporter
	if cfg.UseHTTP {
		var exporterOpts []otlptracehttp.Option

		logger.Info("starting HTTP exporter")
		exporterOpts, err := httpExporterOptions(cfg)
		if err != nil {
			return err
		}
		exp, err = otlptracehttp.New(context.Background(), exporterOpts...)
		if err != nil {
			return fmt.Errorf("failed to obtain OTLP HTTP exporter: %w", err)
		}
	} else {
		var exporterOpts []otlptracegrpc.Option

		logger.Info("starting gRPC exporter")
		exporterOpts, err := grpcExporterOptions(cfg)
		if err != nil {
			return err
		}
		exp, err = otlptracegrpc.New(context.Background(), exporterOpts...)
		if err != nil {
			return fmt.Errorf("failed to obtain OTLP gRPC exporter: %w", err)
		}
	}

	defer func() {
		logger.Info("stopping the exporter")
		if tempError := exp.Shutdown(context.Background()); tempError != nil {
			logger.Error("failed to stop the exporter", zap.Error(tempError))
		}
	}()

	var ssp sdktrace.SpanProcessor
	if cfg.Batch {
		ssp = sdktrace.NewBatchSpanProcessor(exp, sdktrace.WithBlocking())
		defer func() {
			logger.Info("stop the batch span processor")
			if tempError := ssp.Shutdown(context.Background()); tempError != nil {
				logger.Error("failed to stop the batch span processor", zap.Error(tempError))
			}
		}()
	}

	var attributes []attribute.KeyValue
	// may be overridden by `--otlp-attributes service.name="foo"`
	attributes = append(attributes, semconv.ServiceNameKey.String(cfg.ServiceName))
	attributes = append(attributes, cfg.GetAttributes()...)

	tracerProvider := sdktrace.NewTracerProvider(
		sdktrace.WithResource(resource.NewWithAttributes(semconv.SchemaURL, attributes...)),
	)

	if cfg.Batch {
		tracerProvider.RegisterSpanProcessor(ssp)
	}
	otel.SetTracerProvider(tracerProvider)

	if err := Run(cfg, logger); err != nil {
		logger.Error("failed to execute the test scenario.", zap.Error(err))
		return err
	}

	return nil
}