fix: add signal handling to SyncFlags grpc (open-feature#1176)

Signed-off-by: Giovanni Liva <[email protected]>

core/pkg/service/sync/handler.go

@@ -17,6 +17,8 @@ type handler struct {
 	syncv1grpc.UnimplementedFlagSyncServiceServer
 	syncStore subscriptions.Manager
 	logger    *logger.Logger
+	// ctx is used to handle SIG[INT|TERM]
+	ctx context.Context
 }
 
 func (nh *handler) SyncFlags(
@@ -40,6 +42,8 @@ func (nh *handler) SyncFlags(
 			}
 		case <-server.Context().Done():
 			return nil
+		case <-nh.ctx.Done():
+			return nil
 		}
 	}
 }
@@ -64,6 +68,8 @@ type oldHandler struct {
 	rpc.UnimplementedFlagSyncServiceServer
 	syncStore subscriptions.Manager
 	logger    *logger.Logger
+	// ctx is used to handle SIG[INT|TERM]
+	ctx context.Context
 }
 
 func (l *oldHandler) FetchAllFlags(ctx context.Context, req *syncv1.FetchAllFlagsRequest) (
@@ -102,6 +108,8 @@ func (l *oldHandler) SyncFlags(
 			}
 		case <-stream.Context().Done():
 			return nil
+		case <-l.ctx.Done():
+			return nil
 		}
 	}
 }

core/pkg/service/sync/server.go

@@ -35,14 +35,16 @@ type Server struct {
 	metricServerReady bool
 }
 
-func NewServer(logger *logger.Logger, store subscriptions.Manager) *Server {
+func NewServer(ctx context.Context, logger *logger.Logger, store subscriptions.Manager) *Server {
 	theOldHandler := &oldHandler{
 		logger:    logger,
 		syncStore: store,
+		ctx:       ctx,
 	}
 	theNewHandler := &handler{
 		logger:    logger,
 		syncStore: store,
+		ctx:       ctx,
 	}
 	return &Server{
 		oldHandler: theOldHandler,

flagd-proxy/cmd/start.go

@@ -63,7 +63,7 @@ var startCmd = &cobra.Command{
 		ctx, _ := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
 
 		syncStore := subscriptions.NewManager(ctx, logger)
-		s := syncServer.NewServer(logger, syncStore)
+		s := syncServer.NewServer(ctx, logger, syncStore)
 
 		cfg := service.Configuration{
 			ReadinessProbe: func() bool { return true },