How to get the original TCP connection hostname in Python Twisted?

Question

With Twisted's TCP mechanisms, when a protocol is created, the only information about the peer is its IP address and port. How can I retrieve the original hostname that I tried to connect with?

reactor.connectTCP('somehost.com', 80, MyFactory)

How can I ever get 'somehost.com' through a callback somehow? In other words, connectTCP returns an IConnector (whatever it does) - how do I correspond this to something tangible in a callback, since no deferreds are used?

Answer 1

The simple answer is, "Record it yourself".

Updating your example:

myfactory = MyFactory(connecthost='somehost.com')
reactor.connectTCP(myfactory.connecthost, 80, myfactory)

If it's an important piece of information, you should be explicitly passing it around explicitly, in much the same way as you would pass around details about why you connected to a host and what to do once a connection is established.

Answer 2

Jerub's answer makes sense semantically. After digging through Twisted code, there is a more expedient and direct way of doing specifically what I'm trying to achieve.

In protocol:

def connectionMade(self):
    # This is the original connector that connectTCP returned
    connector = self.transport.connector

    # This is the original destination requested
    connector.getDestination()