From ac2b458990ebf417b57ec902b6296217cee26240 Mon Sep 17 00:00:00 2001
From: Den <denis100703@gmail.com>
Date: Sun, 21 Jul 2024 02:50:43 +0300
Subject: [PATCH] graceful shutdown implemented

---
 cmd/server/main.go        | 16 +++------
 internal/server/server.go | 71 +++++++++++++++++++++++++--------------
 2 files changed, 50 insertions(+), 37 deletions(-)

diff --git a/cmd/server/main.go b/cmd/server/main.go
index 3902c06..8d72b26 100644
--- a/cmd/server/main.go
+++ b/cmd/server/main.go
@@ -10,20 +10,12 @@ import (
 
 func main() {
 	cfg := config.MustLoad()
-
 	log := prettylog.SetupLogger(cfg.Env)
-	log.Info("starting librakeeper srv", slog.String("env", cfg.Env), slog.Int("port", cfg.Server.Port))
-
-	// Create and initialize the srv
-	srv := server.NewServer(cfg, log)
-	if err := srv.Initialize(); err != nil {
-		log.Error("failed to initialize srv", slog.Any("error", err))
-		os.Exit(1)
-	}
+	log.Info("starting librakeeper server", slog.String("env", cfg.Env), slog.Int("port", cfg.Server.Port))
 
-	// Run the srv
-	if err := srv.Run(); err != nil {
-		log.Error("failed to run srv", slog.Any("error", err))
+	// Create and run the server
+	if err := server.NewServer(cfg, log).Run(); err != nil {
+		log.Error("server error", slog.Any("error", err))
 		os.Exit(1)
 	}
 }
diff --git a/internal/server/server.go b/internal/server/server.go
index c8b1901..2d350ca 100644
--- a/internal/server/server.go
+++ b/internal/server/server.go
@@ -38,12 +38,51 @@ func NewServer(config *config.Config, log *slog.Logger) *Server {
 	return &Server{
 		config: config,
 		log:    log,
-		router: gin.New(),
 	}
 }
 
-// Initialize initializes the server components.
-func (s *Server) Initialize() error {
+// Run initializes and starts the HTTP server and handles graceful shutdown.
+func (s *Server) Run() error {
+	if err := s.initialize(); err != nil {
+		return fmt.Errorf("failed to initialize server: %w", err)
+	}
+
+	// Graceful Shutdown
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	go func() {
+		quit := make(chan os.Signal, 1)
+		signal.Notify(quit, syscall.SIGINT, syscall.SIGTERM)
+		<-quit
+		s.log.Info("received shutdown signal")
+		cancel()
+	}()
+
+	return s.runHTTPServer(ctx)
+}
+
+func (s *Server) runHTTPServer(ctx context.Context) error {
+	go func() {
+		if err := s.httpServer.ListenAndServe(); err != nil && !errors.Is(err, http.ErrServerClosed) {
+			s.log.Error("failed to start server", slog.Any("error", err))
+		}
+	}()
+
+	s.log.Info("server started successfully, press Ctrl+C to stop")
+
+	<-ctx.Done() // Block until the context is canceled (shutdown signal)
+
+	s.log.Info("shutting down server...")
+
+	shutdownCtx, done := context.WithTimeout(ctx, 5*time.Second)
+	defer done()
+
+	return s.httpServer.Shutdown(shutdownCtx) // Graceful shutdown
+}
+
+// initialize initializes the server components.
+func (s *Server) initialize() error {
 	// Initialize Firebase
 	err := auth.InitializeFirebase(s.config.Auth.ConfigPath)
 	if err != nil {
@@ -60,7 +99,7 @@ func (s *Server) Initialize() error {
 		grpc.WithTransportCredentials(insecure.NewCredentials()),
 	)
 	if err != nil {
-		panic(err)
+		return fmt.Errorf("failed to connect to gRPC server: %w", err)
 	}
 
 	bookRepo := mongo.NewBookRepo(db, s.log, "user_books")
@@ -80,11 +119,13 @@ func (s *Server) Initialize() error {
 
 	// Configure CORS
 	corsConfig := cors.Config{
-		AllowOrigins:     s.config.Server.AllowedOrigins, // Get origins from config
+		AllowOrigins:     s.config.Server.AllowedOrigins,
 		AllowMethods:     []string{"GET", "POST", "PUT", "DELETE", "OPTIONS"},
 		AllowHeaders:     []string{"Origin", "Content-Type", "Authorization"},
 		AllowCredentials: true,
 	}
+
+	s.router = gin.New()
 	s.router.Use(gin.Logger(), gin.Recovery(), cors.New(corsConfig))
 	routes.SetupRoutes(s.router, h)
 
@@ -95,23 +136,3 @@ func (s *Server) Initialize() error {
 
 	return nil
 }
-
-// Run starts the HTTP server and handles graceful shutdown.
-func (s *Server) Run() error {
-	go func() {
-		if err := s.httpServer.ListenAndServe(); err != nil && !errors.Is(err, http.ErrServerClosed) {
-			s.log.Error("failed to start server", slog.Any("error", err))
-		}
-	}()
-
-	quit := make(chan os.Signal, 1)
-	signal.Notify(quit, syscall.SIGINT, syscall.SIGTERM)
-	<-quit
-
-	s.log.Info("shutting down server...")
-
-	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
-	defer cancel()
-
-	return s.httpServer.Shutdown(ctx)
-}