How can I get the raw request body in a Google Cloud Function?

Question

I need the raw request body to be able to SHA-1 digest it to validate the Facebook webhook X-Hub-Signature header that\'s passed along with the request to my Firebase Functi

Answer 1

Unfortunately the default middleware currently provides no way to get the raw request body. See: Access to unparsed JSON body in HTTP Functions (#36252545).

Answer 2

 const escapeHtml = require('escape-html');

/**
 * Responds to an HTTP request using data from the request body parsed according
 * to the "content-type" header.
 *
 * @param {Object} req Cloud Function request context.
 * @param {Object} res Cloud Function response context.
 */
exports.helloContent = (req, res) => {
  let name;

  switch (req.get('content-type')) {
    // '{"name":"John"}'
    case 'application/json':
      ({name} = req.body);
      break;

    // 'John', stored in a Buffer
    case 'application/octet-stream':
      name = req.body.toString(); // Convert buffer to a string
      break;

    // 'John'
    case 'text/plain':
      name = req.body;
      break;

    // 'name=John' in the body of a POST request (not the URL)
    case 'application/x-www-form-urlencoded':
      ({name} = req.body);
      break;
  }

  res.status(200).send(`Hello ${escapeHtml(name || 'World')}!`);
};

Answer 3

Now you can get the raw body from req.rawBody. It returns Buffer. See documentation for more details.

Thanks to Nobuhito Kurose for posting this in comments.