Symfony\Component\HttpKernel\Kernel::getRootDir PHP Method

    public function getRootDir()
    {
        return $this->rootDir;
    }

 /**
  * Generate PDF-file of ticket
  *
  * @param string $html       HTML to generate pdf
  * @param string $outputFile Name of output file
  *
  * @return mixed
  */
 public function generatePdfFile($html, $outputFile)
 {
     // Override default fonts directory for mPDF
     define('_MPDF_SYSTEM_TTFONTS', realpath($this->kernel->getRootDir() . '/../web/fonts/open-sans/') . '/');
     /** @var \TFox\MpdfPortBundle\Service\MpdfService $mPDFService */
     $mPDFService = $this->container->get('tfox.mpdfport');
     $mPDFService->setAddDefaultConstructorArgs(false);
     $constructorArgs = array('mode' => 'BLANK', 'format' => 'A5-L', 'margin_left' => 0, 'margin_right' => 0, 'margin_top' => 0, 'margin_bottom' => 0, 'margin_header' => 0, 'margin_footer' => 0);
     $mPDF = $mPDFService->getMpdf($constructorArgs);
     // Open Sans font settings
     $mPDF->fontdata['opensans'] = array('R' => 'OpenSans-Regular.ttf', 'B' => 'OpenSans-Bold.ttf', 'I' => 'OpenSans-Italic.ttf', 'BI' => 'OpenSans-BoldItalic.ttf');
     $mPDF->sans_fonts[] = 'opensans';
     $mPDF->available_unifonts[] = 'opensans';
     $mPDF->available_unifonts[] = 'opensansI';
     $mPDF->available_unifonts[] = 'opensansB';
     $mPDF->available_unifonts[] = 'opensansBI';
     $mPDF->default_available_fonts[] = 'opensans';
     $mPDF->default_available_fonts[] = 'opensansI';
     $mPDF->default_available_fonts[] = 'opensansB';
     $mPDF->default_available_fonts[] = 'opensansBI';
     $mPDF->SetDisplayMode('fullpage');
     $mPDF->WriteHTML($html);
     $pdfFile = $mPDF->Output($outputFile, 'S');
     return $pdfFile;
 }