Allow redirects not configurable in sessions

I have an application I need to reach behind a firewall, I've set up a tunnel to this application via SSH running on my machine which forwards all connections from 127.0.0.1:1234 to 192.168.1.10:80. Whenever I make a request to my application, it redirects me to a login page first.

The issue with this is that all redirect URL's have the 192.168.1.10 hostname, which requests tries to follow and inevitably crashes (as this host does not exist on my network).

I tried to set allow_redirects to False on my session by overriding the request method, but the session source hard-codes the allow_redirects option to True if it isn't explicitly set when calling get, head and options (source)

Expected Result

I expected no redirect to be followed, but rather that that the request ends after the first response. I expected the allow_redirects option to be configurable in sessions like the verify flag is (source)

Actual Result

The 302 was resolved, and attempted to redirect me to a nonexistent host, leading to a connection error exception.

Reproduction Steps

import requests


class Example(requests.Session):
    def __init__(self, allow_redirects=False, *args, **kwargs):
        super(Example, self).__init__(*args, **kwargs)
        self.allow_redirects = allow_redirects

    def request(self, *args, **kwargs):
        kwargs.setdefault('allow_redirects', self.allow_redirects)
        return super(Example, self).request(*args, **kwargs)


sess = Example()
sess.get('http://127.0.0.1:1234')  # ConnectionError ... 192.168.1.10 connection refused (redirected)

System Information

$ python -m requests.help

{
  "chardet": {
    "version": "3.0.4"
  },
  "cryptography": {
    "version": ""
  },
  "idna": {
    "version": "2.8"
  },
  "implementation": {
    "name": "CPython",
    "version": "3.6.0"
  },
  "platform": {
    "release": "10",
    "system": "Windows"
  },
  "pyOpenSSL": {
    "openssl_version": "",
    "version": null
  },
  "requests": {
    "version": "2.21.0"
  },
  "system_ssl": {
    "version": "100020af"
  },
  "urllib3": {
    "version": "1.24.1"
  },
  "using_pyopenssl": false
}

Start by reading requests/sessions.py around the get, head, options, and session configuration code referenced in the issue, especially the areas near lines 545 and 625. Verify how session defaults are applied and add configurable redirect behavior so a session can stop at the first response; done means the provided Example reproduction no longer follows the 302.