service: add react web app serving option

Signed-off-by: Adphi <philippe.adrien.nousse@gmail.com>

service/web.go

@@ -5,6 +5,8 @@ import (
 	"time"
 
 	"github.com/improbable-eng/grpc-web/go/grpcweb"
+
+	"go.linka.cloud/grpc/react"
 )
 
 var defaultWebOptions = []grpcweb.Option{
@@ -33,3 +35,15 @@ func (s *service) grpcWeb(opts ...grpcweb.Option) error {
 	}
 	return nil
 }
+
+func (s *service) reactApp() error {
+	if !s.opts.hasReactUI {
+		return nil
+	}
+	h, err := react.NewHandler(s.opts.reactUI, s.opts.reactUISubPath)
+	if err != nil {
+		return err
+	}
+	s.opts.mux.Handle("/", h)
+	return nil
+}