public function actionFileProvider($machine, $buildToken, $fileId)
    {
        $build = $this->ensureBuild($machine, $buildToken);
        
        if ($build) {
            if (!is_numeric($fileId)) {
                throw new ForbiddenHttpException("Invalid file id input.");
            }
            
            $file = Yii::$app->storage->getFile($fileId);
            /* @var $file \luya\admin\file\Item */
            if ($file->fileExists) {
                return Yii::$app->response->sendFile($file->serverSource, null, ['mimeType' => $file->mimeType])->send();
            }
            
            throw new NotFoundHttpException("The requested file '".$file->serverSource."' does not exist in the storage folder.");
        }
    }