fix: graceful shutdown in http and wails modes

README.md

@@ -46,6 +46,8 @@ Go to `/frontend`
 
 `unset GTK_PATH && wails dev -tags "wails"`
 
+_If you get a blank screen the first load, close the window and start the app again_
+
 #### Wails Production build
 
 `wails build -tags "wails"`

main.go

@@ -28,7 +28,7 @@ import (
 )
 
 // TODO: move to service.go
-func NewService(wg *sync.WaitGroup) *Service {
+func NewService(ctx context.Context) *Service {
 	// Load config from environment variables / .env file
 	godotenv.Load(".env")
 	cfg := &Config{}
@@ -118,13 +118,16 @@ func NewService(wg *sync.WaitGroup) *Service {
 	}
 
 	log.Infof("Starting nostr-wallet-connect. npub: %s hex: %s", npub, identityPubkey)
-	ctx := context.Background()
 	ctx, _ = signal.NotifyContext(ctx, os.Interrupt)
 
+	var wg sync.WaitGroup
+	wg.Add(1)
+
 	svc := &Service{
 		cfg: cfg,
 		db:  db,
 		ctx: ctx,
+		wg:  &wg,
 	}
 
 	err = svc.setupDbConfig()
@@ -156,7 +159,9 @@ func NewService(wg *sync.WaitGroup) *Service {
 
 		relay, err := nostr.RelayConnect(ctx, cfg.Relay, nostr.WithNoticeHandler(svc.noticeHandler))
 		if err != nil {
-			svc.Logger.Fatal(err)
+			svc.Logger.Errorf("Failed to connect to relay: %v", err)
+			wg.Done()
+			return
 		}
 
 		//publish event with NIP-47 info
@@ -186,11 +191,19 @@ func NewService(wg *sync.WaitGroup) *Service {
 			//err being nil means that the context was canceled and we should exit the program.
 			break
 		}
+		svc.Logger.Info("Disconnecting from relay...")
 		err = relay.Close()
 		if err != nil {
 			svc.Logger.Error(err)
 		}
-		svc.Logger.Info("Graceful shutdown completed. Goodbye.")
+		if svc.lnClient != nil {
+			svc.Logger.Info("Shutting down LN backend...")
+			err = svc.lnClient.Shutdown()
+			if err != nil {
+				svc.Logger.Error(err)
+			}
+		}
+		svc.Logger.Info("Relay subroutine ended")
 		wg.Done()
 	}()
 

main_http.go

@@ -9,7 +9,6 @@ import (
 	"context"
 	"fmt"
 	"net/http"
-	"sync"
 	"time"
 
 	echologrus "github.com/davrux/echo-logrus/v4"
@@ -21,10 +20,8 @@ import (
 // this function will only be executed if no wails tag is set
 func main() {
 	log.Info("NWC Starting in HTTP mode")
-	var wg sync.WaitGroup
-	wg.Add(1)
-
-	svc := NewService(&wg)
+	ctx := context.Background()
+	svc := NewService(ctx)
 
 	if svc.cfg.CookieSecret == "" {
 		svc.Logger.Fatalf("required key COOKIE_SECRET missing value")
@@ -38,16 +35,17 @@ func main() {
 	//start Echo server
 	go func() {
 		if err := e.Start(fmt.Sprintf(":%v", svc.cfg.Port)); err != nil && err != http.ErrServerClosed {
-			e.Logger.Fatal("shutting down the server")
+			e.Logger.Fatalf("shutting down the server: %v", err)
 		}
-		//handle graceful shutdown
-		<-svc.ctx.Done()
-		ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
-		defer cancel()
-		e.Shutdown(ctx)
-		svc.Logger.Info("Echo server exited")
-		wg.Done()
 	}()
-
-	wg.Wait()
+	//handle graceful shutdown
+	<-svc.ctx.Done()
+	svc.Logger.Infof("Shutting down echo server...")
+	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+	defer cancel()
+	e.Shutdown(ctx)
+	svc.Logger.Info("Echo server exited")
+	svc.Logger.Info("Waiting for service to exit...")
+	svc.wg.Wait()
+	svc.Logger.Info("Service exited")
 }

main_wails.go

@@ -4,7 +4,7 @@
 package main
 
 import (
-	"sync"
+	"context"
 
 	log "github.com/sirupsen/logrus"
 )
@@ -13,17 +13,17 @@ import (
 // this function will only be executed if the wails tag is set
 func main() {
 	log.Info("NWC Starting in WAILS mode")
-	var wg sync.WaitGroup
-	wg.Add(1)
+	ctx, cancel := context.WithCancel(context.Background())
+	svc := NewService(ctx)
 
-	svc := NewService(&wg)
+	app := NewApp(svc)
+	LaunchWailsApp(app)
+	svc.Logger.Info("Wails app exited")
 
-	go func() {
-		app := NewApp(svc)
-		LaunchWailsApp(app)
-		wg.Done()
-		svc.Logger.Info("Wails app exited")
-	}()
-
-	wg.Wait()
+	svc.Logger.Info("Cancelling service context...")
+	// cancel the service context
+	cancel()
+	svc.Logger.Info("Waiting for service to exit...")
+	svc.wg.Wait()
+	svc.Logger.Info("Service exited")
 }

service.go

@@ -5,6 +5,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"strings"
+	"sync"
 	"time"
 
 	"github.com/labstack/echo-contrib/session"
@@ -23,6 +24,7 @@ type Service struct {
 	ReceivedEOS bool
 	Logger      *logrus.Logger
 	ctx         context.Context
+	wg          *sync.WaitGroup
 }
 
 func (svc *Service) GetUser(c echo.Context) (user *User, err error) {
@@ -123,7 +125,6 @@ func (svc *Service) StartSubscription(ctx context.Context, sub *nostr.Subscripti
 				}
 			}(event)
 		}
-		svc.Logger.Info("Subscription ended")
 	}()
 
 	select {
@@ -135,7 +136,7 @@ func (svc *Service) StartSubscription(ctx context.Context, sub *nostr.Subscripti
 			svc.Logger.Errorf("Subscription error %v", ctx.Err())
 			return ctx.Err()
 		}
-		svc.Logger.Info("Exiting subscription.")
+		svc.Logger.Info("Exiting subscription...")
 		return nil
 	}
 }