func()

in runtime/gateway.go [403:490]
68 lines of code
11 McCabe index (conditional complexity)

func (gateway *Gateway) Shutdown() {
	// stop accepting incoming requests as soon as shutdown signal is received.
	gateway.isUnhealthy = true

	var swg sync.WaitGroup
	ctx, cancel := context.WithTimeout(context.Background(), gateway.ShutdownTimeout())
	defer cancel()

	ec := make(chan error, 4)

	if gateway.localHTTPServer != gateway.httpServer {
		swg.Add(1)
		go func() {
			defer swg.Done()
			if err := gateway.localHTTPServer.Shutdown(ctx); err != nil {
				ec <- errors.Wrap(err, "error shutting down local http server")
			}
		}()
	}

	// shutdown http server
	swg.Add(1)
	go func() {
		defer swg.Done()
		if err := gateway.httpServer.Shutdown(ctx); err != nil {
			ec <- errors.Wrap(err, "error shutting down http server")
		}
	}()

	// shutdown tchannel server
	swg.Add(1)
	go func() {
		defer swg.Done()
		if err := gateway.shutdownTChannelServerAndClients(ctx); err != nil {
			ec <- errors.Wrap(err, "error shutting down tchannel server or clients")
		}
	}()

	// wait for servers to shutdown before stopping GRPCClientDispatcher
	swg.Wait()

	// stop all grpc clients
	if gateway.GRPCClientDispatcher != nil {
		swg.Add(1)
		go func() {
			defer swg.Done()
			if err := gateway.GRPCClientDispatcher.Stop(); err != nil {
				ec <- errors.Wrap(err, "error stopping gRPC client dispatcher")
			}
		}()
	}

	swg.Wait()

	select {
	case err := <-ec:
		// close ec so that the range ec will not block forever
		close(ec)
		errs := make([]string, 0, cap(ec))
		errs = append(errs, err.Error())
		for e := range ec {
			errs = append(errs, e.Error())
		}
		gateway.Logger.Error(fmt.Sprintf(
			"%d errors when shutting down the servers: %s",
			len(errs), strings.Join(errs, ";")),
		)
		gateway.RootScope.Counter("shutdown.failure").Inc(1)
	default:
		gateway.Logger.Info("servers are shut down gracefully")
		gateway.RootScope.Counter("shutdown.success").Inc(1)
	}

	_ = gateway.tracerCloser.Close()
	gateway.metricsBackend.Flush()
	_ = gateway.scopeCloser.Close()

	// close log files as the last step
	if gateway.loggerFile != nil {
		_ = gateway.loggerFile.Sync()
		_ = gateway.loggerFile.Close()
	}

	// stop collecting runtime metrics
	if gateway.runtimeMetrics != nil {
		gateway.runtimeMetrics.Stop()
	}
}