feat: scaffold go backend foundation

cmd/tutor-api/main.go

@@ -0,0 +1,45 @@
+package main
+
+import (
+	"context"
+	"errors"
+	"log"
+	"net/http"
+	"os"
+	"os/signal"
+	"syscall"
+	"time"
+
+	"tutor/internal/app"
+	"tutor/internal/config"
+)
+
+func main() {
+	cfg := config.LoadFromEnv()
+	server := app.NewServer(cfg)
+
+	errs := make(chan error, 1)
+	go func() {
+		log.Printf("starting tutor-api on %s", cfg.HTTPAddr)
+		errs <- server.ListenAndServe()
+	}()
+
+	stop := make(chan os.Signal, 1)
+	signal.Notify(stop, os.Interrupt, syscall.SIGTERM)
+
+	select {
+	case sig := <-stop:
+		log.Printf("received signal %s; shutting down", sig)
+	case err := <-errs:
+		if err != nil && !errors.Is(err, http.ErrServerClosed) {
+			log.Fatalf("server error: %v", err)
+		}
+		return
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+	if err := server.Shutdown(ctx); err != nil {
+		log.Fatalf("shutdown error: %v", err)
+	}
+}