Using Python “requests” with existing socket connection

Question

The Python “requests” library is currently all the rage, because of the beautiful interface that it provides for making HTTP requests — but beneath it there seems to be many

Answer 1

Go straight to the urllib3 library; it holds a connection pool in the urllib3.connectionpool module.

You could replace the pool or adjust it by hacking the poolmanager module perhaps.

Answer 2

The following code needs requests from git (especially requests.packages.urllib3.poolmanager.PoolManager._new_pool())

I tested it using ncat -v -l 127.0.0.1 8000

The problem is the fact, that the connection isn't opened by urllib3 but by httplib from the standard library.

import socket
import requests
from requests.adapters import HTTPAdapter
from requests.packages.urllib3 import PoolManager, HTTPConnectionPool

try:
    from http.client import HTTPConnection
except ImportError:
    from httplib import HTTPConnection


class MyAdapter(HTTPAdapter):
    def init_poolmanager(self, connections, maxsize):
        self.poolmanager = MyPoolManager(num_pools=connections,
                                         maxsize=maxsize)


class MyPoolManager(PoolManager):
    def _new_pool(self, scheme, host, port):
        # Important!
        if scheme == 'http' and host == my_host and port == my_port:
            return MyHTTPConnectionPool(host, port, **self.connection_pool_kw)
        return super(PoolManager, self)._new_pool(self, scheme, host, port)


class MyHTTPConnectionPool(HTTPConnectionPool):
    def _new_conn(self):
        self.num_connections += 1
        return MyHTTPConnection(host=self.host,
                            port=self.port,
                            strict=self.strict)


class MyHTTPConnection(HTTPConnection):
    def connect(self):
        """Connect to the host and port specified in __init__."""
        # Original
        # self.sock = socket.create_connection((self.host, self.port),
        #                                    self.timeout, self.source_address)
        # Important!
        self.sock = my_socket
        if self._tunnel_host:
            self._tunnel()


if __name__ == '__main__':
    import time

    my_host = '127.0.0.1'
    my_port = 8000

    my_socket = socket.create_connection((my_host, my_port))
    time.sleep(4)
    s = requests.Session()
    s.mount('http://', MyAdapter())
    s.get('http://127.0.0.1:8000/foo')

Edit:

Or direct monkeypatching of the connectionpool:

class MyHTTPConnection(HTTPConnection):
    def connect(self):
        self.sock = my_socket
        if self._tunnel_host:
            self._tunnel()

requests.packages.urllib3.connectionpool.HTTPConnection = MyHTTPConnection

if __name__ == '__main__':
    my_host = '127.0.0.1'
    my_port = 8000

    my_socket = socket.create_connection((my_host, my_port))
    requests.get('http://127.0.0.1:8000/foo')