The pipe forwards the client host.

[royalpinto]

Describe the bug

• Node.js version: v14
• OS & version: macOS (10)
• Got version: 11.8.2

Actual behavior

The pipe request forwards all the client headers including the "Host"

Expected behavior

The pipe request should forwards all the client headers but not the "Host"

Code to reproduce

npm install got nock express request 

const got = require('got')
const nock = require('nock')
const express = require('express')
const request = require('request')

nock('http://www.google.com')
  .persist()
  .get('/echo')
  .reply(function (uri, body) {
    return [200, { headers: this.req.headers }]
  })

const proxy = express()
proxy.get('/got/pipe', (req, res) => {
  req.pipe(got.stream('http://www.google.com/echo')).pipe(res)
})

proxy.get('/request/pipe', (req, res) => {
  req.pipe(request.get('http://www.google.com/echo')).pipe(res)
})

proxy.listen(3000, () => {
  console.log('Try the following:')
  console.log("curl -H 'Hi: Bye' -H 'Host: Value' 'http://127.0.0.1:3000/got/pipe'")
  console.log("curl -H 'Hi: Bye' -H 'Host: Value' 'http://127.0.0.1:3000/request/pipe'")
})

Output

// With Got
curl -H 'Hi: Bye' -H 'Host: Value' 'http://127.0.0.1:3000/got/pipe'
{
    "headers": {
        "accept": "*/*",
        "accept-encoding": "gzip, deflate, br",
        "hi": "Bye",
        "host": "Value", **// Should not have been this.**
        "user-agent": "got (https://github.com/sindresorhus/got)"
    }
}

// With Request
curl -H 'Hi: Bye' -H 'Host: Value' 'http://127.0.0.1:3000/request/pipe'
{
    "headers": {
        "accept": "*/*",
        "hi": "Bye",
        "host": "www.google.com",
        "user-agent": "curl/7.64.1"
    }
}

Since the host doesn't match the hostname in the URL, it leads to a certificate error when hitting the actual service than the mocked one.

Checklist

• I have read the documentation.
• I have tried my code with the latest version of Node.js and Got.

[szmarczak]

Simply delete req.headers.host; before piping to got.

got/source/core/index.ts

Lines 1415 to 1422 in f896aa5

	this.on('pipe', source => {
	if (source instanceof IncomingMessage) {
	this.options.headers = {
	...source.headers,
	...this.options.headers
	};
	}
	});

Or you can use a beforeRequest hook:

{
    hooks: {
        beforeRequest: [
            options => {
                delete options.headers.host;
            }
        ]
    }
  }
}

[royalpinto]

Hi @szmarczak ,

Is it not supposed to be handled in the library itself as request does?

[szmarczak]

Is it not supposed to be handled in the library itself as request does?

Why would it be?

[royalpinto]

@szmarczak I am not sure, but I think in most of the cases, the hostname in the URL would be different for proxy and the target, and keeping the hostname the same will lead to certificate errors. I wonder in which cases the hostname needs to be preserved.

[szmarczak]

Well, I'm not actually sure if this is the most popular use case. We need more info.