add:gracefull shutdown context based

cmd/camp/main.go

@@ -1,29 +1,55 @@
 package main
 
 import (
+	"context"
 	"log"
 	"net/http"
+	"os"
+	"time"
 
 	"github.com/codersgyan/camp/internal/contact"
 	"github.com/codersgyan/camp/internal/database"
+	graceful "github.com/codersgyan/camp/internal/shutdown"
 )
 
 func main() {
 	db, err := database.Connect("./camp_data/camp.db")
 	if err != nil {
 		log.Fatal(err)
 	}
-	defer db.Close()
 
-	// run the migration
 	if err := database.RunMigration(db); err != nil {
 		log.Fatal(err)
 	}
 
+	shutdown := graceful.New(10 * time.Second)
+
 	contactRepository := contact.NewRepository(db)
 	contactHandler := contact.NewHandler(contactRepository)
 
+	srv := &http.Server{
+		Addr: ":8080",
+	}
+
 	http.HandleFunc("POST /api/contacts", contactHandler.Create)
 
-	log.Fatal(http.ListenAndServe(":8080", nil))
+	// Register cleanup
+	shutdown.Register(srv.Shutdown)
+	shutdown.Register(db.Close)
+
+	// Start server in goroutine
+	go func() {
+		log.Println("Server running on :8080")
+		if err := srv.ListenAndServe(); err != nil && err != http.ErrServerClosed {
+			log.Fatal(err)
+		}
+	}()
+
+	// Wait for signal
+	exitCode, err := shutdown.Wait(context.Background())
+	if err != nil {
+		log.Fatal(err)
+	}
+	os.Exit(exitCode)
+
 }

internal/contact/handler.go

@@ -4,6 +4,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"net/http"
+	"time"
 )
 
 type Handler struct {
@@ -25,6 +26,7 @@ func (h *Handler) Create(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	time.Sleep(time.Second * 10)
 	w.Header().Set("Content-Type", "application/json")
 
 	createdId, err := h.repo.CreateContactOrUpsertTags(&contactBody)

internal/shutdown/graceful.go

@@ -0,0 +1,63 @@
+package shutdown
+
+import (
+	"context"
+	"os"
+	"os/signal"
+	"syscall"
+	"time"
+)
+
+type GracefulShutdown struct {
+	timeout time.Duration
+	cleanup []func(context.Context) error
+}
+
+func New(timeout time.Duration) *GracefulShutdown {
+	return &GracefulShutdown{
+		timeout: timeout,
+	}
+}
+
+// Register accepts BOTH:
+//
+//	func() error
+//	func(context.Context) error
+func (gs *GracefulShutdown) Register(fn any) {
+	switch f := fn.(type) {
+
+	case func(context.Context) error:
+		gs.cleanup = append(gs.cleanup, f)
+
+	case func() error:
+		wrapped := func(ctx context.Context) error {
+			return f()
+		}
+		gs.cleanup = append(gs.cleanup, wrapped)
+
+	default:
+		panic("Register: invalid function type (must be func() error or func(context.Context) error)")
+	}
+}
+
+func (gs *GracefulShutdown) Wait(ctx context.Context) (int, error) {
+	sigChan := make(chan os.Signal, 1)
+
+	signal.Notify(sigChan, syscall.SIGINT, syscall.SIGTERM)
+
+	sig := <-sigChan
+
+	// Convert to UNIX exit code
+	exitCode := 128 + int(sig.(syscall.Signal))
+
+	// cleanup with timeout
+	cleanupCtx, cancel := context.WithTimeout(ctx, gs.timeout)
+	defer cancel()
+
+	for _, fn := range gs.cleanup {
+		if err := fn(cleanupCtx); err != nil {
+			return exitCode, err
+		}
+	}
+	return exitCode, nil
+}