if (req.body.preReqTemplate) {
    promise = promise.then(() => {
      preReqFileName = tempDir + '/' + Guid.raw();
      preReqParametersFileName = tempDir + '/' + Guid.raw();
      return writeFileHelper(fs, preReqFileName, preReqParametersFileName, req.body.preReqTemplate, req.body.preReqParameters);