better lifecycle management

cmd/any2anexoj-web/main.go

@@ -13,6 +13,7 @@ import (
 	"time"
 
 	"github.com/nmoniz/any2anexoj/internal/web"
+	"golang.org/x/sync/errgroup"
 )
 
 //go:embed all:static
@@ -23,6 +24,7 @@ func main() {
 		slog.Error("any2anexoj-web: fatal error", slog.Any("err", err))
 		os.Exit(1)
 	}
+	slog.Info("shutdown gracefully")
 }
 
 // run wires up the server, installs signal-driven cancellation, and blocks on
@@ -60,26 +62,28 @@ func run() error {
 	ctx, cancel := signal.NotifyContext(context.Background(), os.Kill, os.Interrupt, syscall.SIGTERM)
 	defer cancel()
 
-	errCh := make(chan error, 1)
-	go func() {
-		slog.Info("any2anexoj-web: listening", slog.String("addr", addr))
-		if err := httpServer.ListenAndServe(); err != nil && !errors.Is(err, http.ErrServerClosed) {
-			errCh <- err
-			return
+	eg, ctx := errgroup.WithContext(ctx)
+
+	eg.Go(func() error {
+		slog.Info("listening for http", slog.Any("port", addr))
+		err := httpServer.ListenAndServe()
+		if err != nil && !errors.Is(err, http.ErrServerClosed) {
+			return err
 		}
-		errCh <- nil
-	}()
+		return nil
+	})
+
+	eg.Go(func() error {
+		<-ctx.Done()
 
-	select {
-	case <-ctx.Done():
-		slog.Info("any2anexoj-web: shutting down")
 		shutdownCtx, shutdownCancel := context.WithTimeout(context.Background(), 10*time.Second)
 		defer shutdownCancel()
+
 		if err := httpServer.Shutdown(shutdownCtx); err != nil {
 			return err
 		}
 		return nil
-	case err := <-errCh:
-		return err
-	}
+	})
+
+	return eg.Wait()
 }