code: public function getVclFile($vclTemplatePath) // @codingStandardsIgnoreLine - Unused parameter required due to compatibility with parent class
      {
          $moduleEtcPath = $this->reader->getModuleDir(Dir::MODULE_ETC_DIR, 'Fastly_Cdn');
          $configFilePath = $moduleEtcPath . '/' . $this->_scopeConfig->getValue(self::FASTLY_CONFIGURATION_PATH);
          $directoryRead = $this->readFactory->create($moduleEtcPath);
          $configFilePath = $directoryRead->getRelativePath($configFilePath);
          $data = $directoryRead->readFile($configFilePath);
          return strtr($data, $this->getReplacements());
      }
docs: Return generated magento2_fastly_varnish.vcl configuration file
  
  @param string $vclTemplatePath
  @return string
  @throws \Magento\Framework\Exception\FileSystemException