[Python-ideas] Supporting already opened sockets in our socket-based server classes

[Tarek Ziadé]

Hello

What about allowing all our socket servers -- from SocketServer to 
WSGIServer, to run with an existing socket.

The use case is to make it easier to write applications that use the 
pre-fork model to run several processes against the same socket.

Basically:

- the main process creates a socket, binds it and listen to it
- the main process forks some subprocesses and pass them the socket fd 
value
- each subprocess recreates a socket object using socket.fromfd()   -- 
so it does not bind it
- each subprocess can accept() connection on the socket

I have a working prototype here : 
https://github.com/tarekziade/chaussette/blob/master/chaussette/server.py
(don't look at the code I made it quickly just as a proof of concept)

What I am proposing is the following syntax:

if the host passed to the class is of the form:

     fd://12

The class will try to create a socket object against the file descriptor 
12, and will not bind() it neither accept() it.

How does that sounds ? If people like the idea I can try to build a 
patch for 3.x, and I can certainly release a
backport for 2.x


Cheers
Tarek