🔥 feat: Add support for graceful shutdown timeout in ListenConfig

docs/api/fiber.md

@@ -108,6 +108,7 @@ app.Listen(":8080", fiber.ListenConfig{
 | <Reference id="enableprefork">EnablePrefork</Reference>                 | `bool`                        | When set to true, this will spawn multiple Go processes listening on the same port.                                                           | `false` |
 | <Reference id="enableprintroutes">EnablePrintRoutes</Reference>         | `bool`                        | If set to true, will print all routes with their method, path, and handler.                                                                   | `false` |
 | <Reference id="gracefulcontext">GracefulContext</Reference>             | `context.Context`             | Field to shutdown Fiber by given context gracefully.                                                                                          | `nil`   |
+| <Reference id="gracefulshutdowntimeout">GracefulShutdownTimeout</Reference>| `time.Duration`            | Specifies the maximum duration to wait for the server to gracefully shutdown. When the timeout is reached, the graceful shutdown process is interrupted and forcibly terminated, and the `context.DeadlineExceeded` error is passed to the `OnShutdownError` callback. Set to 0 (default) to disable the timeout and wait indefinitely. | `0`   |
 | <Reference id="listeneraddrfunc">ListenerAddrFunc</Reference>           | `func(addr net.Addr)`         | Allows accessing and customizing `net.Listener`.                                                                                              | `nil`   |
 | <Reference id="listenernetwork">ListenerNetwork</Reference>             | `string`                      | Known networks are "tcp", "tcp4" (IPv4-only), "tcp6" (IPv6-only). WARNING: When prefork is set to true, only "tcp4" and "tcp6" can be chosen. | `tcp4`  |
 | <Reference id="onshutdownerror">OnShutdownError</Reference>             | `func(err error)`             | Allows to customize error behavior when gracefully shutting down the server by given signal.  Prints error with `log.Fatalf()`                | `nil`   |

listen.go

@@ -18,6 +18,7 @@ import (
 	"strconv"
 	"strings"
 	"text/tabwriter"
+	"time"
 
 	"github.com/gofiber/fiber/v3/log"
 	"github.com/mattn/go-colorable"
@@ -37,8 +38,6 @@ const (
 )
 
 // ListenConfig is a struct to customize startup of Fiber.
-//
-// TODO: Add timeout for graceful shutdown.
 type ListenConfig struct {
 	// GracefulContext is a field to shutdown Fiber by given context gracefully.
 	//
@@ -94,6 +93,13 @@ type ListenConfig struct {
 	// Default : ""
 	CertClientFile string `json:"cert_client_file"`
 
+	// When the graceful shutdown begins, use this field to set the timeout
+	// duration. If the timeout is reached, OnShutdownError will be called.
+	// The default value is 0, which means the timeout setting is disabled.
+	//
+	// Default: 0
+	GracefulShutdownTimeout time.Duration `json:"graceful_shutdown_timeout"`
+
 	// When set to true, it will not print out the «Fiber» ASCII art and listening address.
 	//
 	// Default: false
@@ -472,8 +478,17 @@ func (app *App) printRoutesMessage() {
 func (app *App) gracefulShutdown(ctx context.Context, cfg ListenConfig) {
 	<-ctx.Done()
 
-	if err := app.Shutdown(); err != nil { //nolint:contextcheck // TODO: Implement it
+	var err error
+
+	if cfg.GracefulShutdownTimeout != 0 {
+		err = app.ShutdownWithTimeout(cfg.GracefulShutdownTimeout) //nolint:contextcheck // TODO: Implement it
+	} else {
+		err = app.Shutdown() //nolint:contextcheck // TODO: Implement it
+	}
+
+	if err != nil {
 		cfg.OnShutdownError(err)
+		return
 	}
 
 	if success := cfg.OnShutdownSuccess; success != nil {

listen_test.go

@@ -85,7 +85,7 @@ func Test_Listen_Graceful_Shutdown(t *testing.T) {
 		ExpectedStatusCode int
 	}{
 		{Time: 500 * time.Millisecond, ExpectedBody: "example.com", ExpectedStatusCode: StatusOK, ExpectedErr: nil},
-		{Time: 3 * time.Second, ExpectedBody: "", ExpectedStatusCode: StatusOK, ExpectedErr: errors.New("InmemoryListener is already closed: use of closed network connection")},
+		{Time: 3 * time.Second, ExpectedBody: "", ExpectedStatusCode: StatusOK, ExpectedErr: fasthttputil.ErrInmemoryListenerClosed},
 	}
 
 	for _, tc := range testCases {
@@ -115,6 +115,118 @@ func Test_Listen_Graceful_Shutdown(t *testing.T) {
 	mu.Unlock()
 }
 
+// go test -run Test_Listen_Graceful_Shutdown_Timeout
+func Test_Listen_Graceful_Shutdown_Timeout(t *testing.T) {
+	var mu sync.Mutex
+	var shutdownSuccess bool
+	var shutdownTimeoutError error
+
+	app := New()
+
+	app.Get("/", func(c Ctx) error {
+		return c.SendString(c.Hostname())
+	})
+
+	ln := fasthttputil.NewInmemoryListener()
+	errs := make(chan error)
+
+	go func() {
+		ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second)
+		defer cancel()
+
+		errs <- app.Listener(ln, ListenConfig{
+			DisableStartupMessage:   true,
+			GracefulContext:         ctx,
+			GracefulShutdownTimeout: 500 * time.Millisecond,
+			OnShutdownSuccess: func() {
+				mu.Lock()
+				shutdownSuccess = true
+				mu.Unlock()
+			},
+			OnShutdownError: func(err error) {
+				mu.Lock()
+				shutdownTimeoutError = err
+				mu.Unlock()
+			},
+		})
+	}()
+
+	// Server readiness check
+	for i := 0; i < 10; i++ {
+		conn, err := ln.Dial()
+		// To test a graceful shutdown timeout, do not close the connection.
+		if err == nil {
+			_ = conn
+			break
+		}
+		// Wait a bit before retrying
+		time.Sleep(100 * time.Millisecond)
+		if i == 9 {
+			t.Fatalf("Server did not become ready in time: %v", err)
+		}
+	}
+
+	testCases := []struct {
+		ExpectedErr             error
+		ExpectedShutdownError   error
+		ExpectedBody            string
+		Time                    time.Duration
+		ExpectedStatusCode      int
+		ExpectedShutdownSuccess bool
+	}{
+		{
+			Time:                    100 * time.Millisecond,
+			ExpectedBody:            "example.com",
+			ExpectedStatusCode:      StatusOK,
+			ExpectedErr:             nil,
+			ExpectedShutdownError:   nil,
+			ExpectedShutdownSuccess: false,
+		},
+		{
+			Time:                    3 * time.Second,
+			ExpectedBody:            "",
+			ExpectedStatusCode:      StatusOK,
+			ExpectedErr:             fasthttputil.ErrInmemoryListenerClosed,
+			ExpectedShutdownError:   context.DeadlineExceeded,
+			ExpectedShutdownSuccess: false,
+		},
+	}
+
+	for _, tc := range testCases {
+		time.Sleep(tc.Time)
+
+		req := fasthttp.AcquireRequest()
+		req.SetRequestURI("http://example.com")
+
+		client := fasthttp.HostClient{}
+		client.Dial = func(_ string) (net.Conn, error) { return ln.Dial() }
+
+		resp := fasthttp.AcquireResponse()
+		err := client.Do(req, resp)
+
+		if err == nil {
+			require.NoError(t, err)
+			require.Equal(t, tc.ExpectedStatusCode, resp.StatusCode())
+			require.Equal(t, tc.ExpectedBody, string(resp.Body()))
+		} else {
+			require.ErrorIs(t, err, tc.ExpectedErr)
+		}
+
+		mu.Lock()
+		require.Equal(t, tc.ExpectedShutdownSuccess, shutdownSuccess)
+		require.Equal(t, tc.ExpectedShutdownError, shutdownTimeoutError)
+		mu.Unlock()
+
+		fasthttp.ReleaseRequest(req)
+		fasthttp.ReleaseResponse(resp)
+	}
+
+	mu.Lock()
+	err := <-errs
+	require.NoError(t, err)
+	mu.Unlock()
+}
+
 // go test -run Test_Listen_Prefork
 func Test_Listen_Prefork(t *testing.T) {
 	testPreforkMaster = true