Retry initializing TTY size a bit more

I some cases, for example if there is a heavy load, the initialization of the TTY size
would fail. This change makes the cli retry 10 times instead of 5 and we wait
incrementally from 10ms to 100ms

Relates to docker#3554

Signed-off-by: Djordje Lukic <djordje.lukic@docker.com>

cli/command/container/tty.go

@@ -45,7 +45,7 @@ func resizeTty(ctx context.Context, cli command.Cli, id string, isExec bool) err
 	return resizeTtyTo(ctx, cli.Client(), id, height, width, isExec)
 }
 
-// initTtySize is to init the tty's size to the same as the window, if there is an error, it will retry 5 times.
+// initTtySize is to init the tty's size to the same as the window, if there is an error, it will retry 10 times.
 func initTtySize(ctx context.Context, cli command.Cli, id string, isExec bool, resizeTtyFunc func(ctx context.Context, cli command.Cli, id string, isExec bool) error) {
 	rttyFunc := resizeTtyFunc
 	if rttyFunc == nil {
@@ -54,8 +54,8 @@ func initTtySize(ctx context.Context, cli command.Cli, id string, isExec bool, r
 	if err := rttyFunc(ctx, cli, id, isExec); err != nil {
 		go func() {
 			var err error
-			for retry := 0; retry < 5; retry++ {
-				time.Sleep(10 * time.Millisecond)
+			for retry := 0; retry < 10; retry++ {
+				time.Sleep(time.Duration(retry+1) * 10 * time.Millisecond)
 				if err = rttyFunc(ctx, cli, id, isExec); err == nil {
 					break
 				}

cli/command/container/tty_test.go

@@ -25,6 +25,6 @@ func TestInitTtySizeErrors(t *testing.T) {
 	ctx := context.Background()
 	cli := test.NewFakeCli(&fakeClient{containerExecResizeFunc: fakeContainerExecResizeFunc})
 	initTtySize(ctx, cli, "8mm8nn8tt8bb", true, fakeResizeTtyFunc)
-	time.Sleep(100 * time.Millisecond)
+	time.Sleep(750 * time.Millisecond)
 	assert.Check(t, is.Equal(expectedError, cli.ErrBuffer().String()))
 }