How to Get the Request Source Hostname in Node.js? or Node.js Request Source Hostname: How to Retriev

`req.headers.host` is the standard, but yeah, proxies break it.

For nodejs request source hostname, I’d suggest:
1. Check `x-forwarded-host` first.
2. Fall back to `host`.
3. Validate the value if security matters.

Here’s a quick example:
```javascript
const host = req.headers['x-forwarded-host'] || req.headers.host;
if (!isValidHost(host)) throw new Error('Invalid host');
```