appUtility_test.go

package integration_test_application

import (
	"context"
	"os"
	"os/signal"
	"syscall"

	"code.fbi.h-da.de/danet/gosdn/application-framework/event"
	"code.fbi.h-da.de/danet/gosdn/application-framework/registration"
	"github.com/sirupsen/logrus"
	"google.golang.org/grpc"
)

// Application is an example for a sdn application.
type Application struct {
	eventService   event.ServiceInterface
	stopChannel    chan os.Signal
	grpcClientConn *grpc.ClientConn
	eventChannel   chan event.Event
}

func NewApplication(ctx context.Context, grpcClientConn *grpc.ClientConn, controllerAddress string, topics []event.Topic) *Application {
	queueCredentials, err := registration.Register(ctx, controllerAddress, "integration-test-application", "SecurePresharedToken")
	if err != nil {
		logrus.Errorf("failed to register application on control plane. %v", err)
		os.Exit(1)
	}

	eventService, err := event.NewEventService(
		queueCredentials,
		topics,
	)
	if err != nil {
		logrus.Errorf("failed to create event service. %v", err)
		os.Exit(1)
	}

	return &Application{
		eventService:   eventService,
		stopChannel:    make(chan os.Signal, 1),
		grpcClientConn: grpcClientConn,
		eventChannel:   make(chan event.Event, 1),
	}
}

// Run runs the application.
func (a *Application) Run(eventTypeCallbackTuples []event.TypeToCallbackTuple) {
	signal.Notify(a.stopChannel, os.Interrupt, syscall.SIGTERM)

	a.eventService.SubscribeToEventType(eventTypeCallbackTuples)
	a.eventService.SetupEventReciever(a.stopChannel)

	var forever chan struct{}

	go func() {
		for {
			select {
			case <-a.stopChannel:
				close(forever)
				_ = a.grpcClientConn.Close()

				return
			}
		}
	}()

	<-forever
}

func (a *Application) callback(event *event.Event) {
	a.eventChannel <- *event
}