Retry command execution when VM session is locked (#8483)

builder/virtualbox/common/driver_4_2.go

@@ -165,9 +165,6 @@ func (d *VBox42Driver) Stop(name string) error {
 		return err
 	}
 
-	// We sleep here for a little bit to let the session "unlock"
-	time.Sleep(2 * time.Second)
-
 	return nil
 }
 
@@ -189,7 +186,18 @@ func (d *VBox42Driver) SuppressMessages() error {
 }
 
 func (d *VBox42Driver) VBoxManage(args ...string) error {
-	_, err := d.VBoxManageWithOutput(args...)
+	ctx := context.TODO()
+	err := retry.Config{
+		Tries: 5,
+		ShouldRetry: func(err error) bool {
+			return strings.Contains(err.Error(), "VBOX_E_INVALID_OBJECT_STATE")
+		},
+		RetryDelay: func() time.Duration { return 2 * time.Minute },
+	}.Run(ctx, func(ctx context.Context) error {
+		_, err := d.VBoxManageWithOutput(args...)
+		return err
+	})
+
 	return err
 }
 

builder/virtualbox/common/shutdown_config.go

@@ -41,5 +41,9 @@ func (c *ShutdownConfig) Prepare(ctx *interpolate.Context) []error {
 		c.ShutdownTimeout = 5 * time.Minute
 	}
 
+	if c.PostShutdownDelay == 0 {
+		c.PostShutdownDelay = 2 * time.Second
+	}
+
 	return nil
 }

builder/virtualbox/common/shutdown_config_test.go

@@ -49,8 +49,8 @@ func TestShutdownConfigPrepare_PostShutdownDelay(t *testing.T) {
 	if len(errs) > 0 {
 		t.Fatalf("err: %#v", errs)
 	}
-	if c.PostShutdownDelay.Nanoseconds() != 0 {
+	if c.PostShutdownDelay != 2*time.Second {
-		t.Fatalf("bad: %s", c.PostShutdownDelay)
+		t.Fatalf("bad: PostShutdownDelay should be 2 seconds but was %s", c.PostShutdownDelay)
 	}
 
 	// Test with a good one