implement graceful shutdown (dapr#260)

Signed-off-by: Naveen Ramanathan <[email protected]>

service/common/service.go

@@ -41,6 +41,8 @@ type Service interface {
 	Start() error
 	// Stop stops the previously started service.
 	Stop() error
+	// Gracefully stops the previous started service
+	GracefulStop() error
 }
 
 type (

service/grpc/service.go

@@ -65,6 +65,7 @@ type Server struct {
 	topicRegistrar  internal.TopicRegistrar
 	bindingHandlers map[string]common.BindingInvocationHandler
 	authToken       string
+	grpcServer      *grpc.Server
 }
 
 func (s *Server) RegisterActorImplFactory(f actor.Factory, opts ...config.Option) {
@@ -75,10 +76,16 @@ func (s *Server) RegisterActorImplFactory(f actor.Factory, opts ...config.Option
 func (s *Server) Start() error {
 	gs := grpc.NewServer()
 	pb.RegisterAppCallbackServer(gs, s)
+	s.grpcServer = gs
 	return gs.Serve(s.listener)
 }
 
 // Stop stops the previously started service.
 func (s *Server) Stop() error {
 	return s.listener.Close()
 }
+
+func (s *Server) GracefulStop() error {
+	s.grpcServer.GracefulStop()
+	return nil
+}

service/http/service.go

@@ -81,6 +81,10 @@ func (s *Server) Stop() error {
 	return s.httpServer.Shutdown(ctxShutDown)
 }
 
+func (s *Server) GracefulStop() error {
+	return s.Stop()
+}
+
 func setOptions(w http.ResponseWriter, r *http.Request) {
 	w.Header().Set("Access-Control-Allow-Origin", "*")
 	w.Header().Set("Access-Control-Allow-Methods", "POST,OPTIONS")