Get client domain in request

Question

I have public GCP cloud function:

exports.helloWorld = (req, res) => {
  let message = req.query.message || req.body.message || 'Hello World!';
  console.log(req.headers.origin);
  res.status(200).send(message);
};

and I need to get domains of clients, which will call this function. 'req.headers.origin' returns 'undefined' and 'req.headers.host' returns link of my cloud function.

Answer 1

When your function is called, the req parameter contains the Request object from Express. The documentation for this can be found here . This object contains a field called ip which is the IP address of the caller.

We will also find the same IP address in the header x-forwarded-for .

We won't find the domain name (eg. xyz.com) in the data. I think the best you will find is the callers IP address. You may be able to perform an IP address lookup using DNS... see the reverse() function.