[Twisted-Python] Queries about connecting to a XML-RPC server over IPv6

[Amit Saha]

----- Original Message -----
> From: "Phil Mayers" <p.mayers at imperial.ac.uk>
> To: twisted-python at twistedmatrix.com
> Sent: Thursday, December 12, 2013 10:33:21 PM
> Subject: Re: [Twisted-Python] Queries about connecting to a XML-RPC server over IPv6
> 
> On 12/12/13 12:23, Amit Saha wrote:
> >
> >
> > ----- Original Message -----
> >> From: "Amit Saha" <asaha at redhat.com>
> >> To: "Twisted general discussion" <twisted-python at twistedmatrix.com>
> >> Sent: Tuesday, December 10, 2013 11:59:27 AM
> >> Subject: Re: [Twisted-Python] Queries about connecting to a XML-RPC server
> >> over IPv6
> >>
> >>
> >>
> >> ----- Original Message -----
> >>> From: "Phil Mayers" <p.mayers at imperial.ac.uk>
> >>> To: twisted-python at twistedmatrix.com
> >>> Sent: Monday, December 9, 2013 7:33:17 PM
> >>> Subject: Re: [Twisted-Python] Queries about connecting to a XML-RPC
> >>> server
> >>> over IPv6
> >>>
> >>> On 09/12/13 05:28, Amit Saha wrote:
> >>>
> >>>> proxy = Proxy('http://localhost6:8000')
> >>>> proxy.callRemote('my_proxy_method').addCallbacks(printValue, printError)
> >>>>
> >>>>
> >>>> When I run it, i get "No route to host: 101, Network is unreachable".
> >>>>
> >>>> However, 'curl -6 localhost:8000' succeeds. What could be going on here?
> >>>
> >>> The IPv6 support in Twisted is very new - check your version even *has*
> >>> it - and it's still a work in progress. You might find that you can't do
> >>> this. I'd have to read the code to be sure and I don't have time right
> >>> now, but my guess is that t.w.xmlrpc isn't "getaddrinfo"-ised so won't
> >>> connect to IPv6 names.
> >>>
> >>> If your version of Twisted supports it, you could probably work around
> >>> this by sub-classing Proxy and calling reactor.connectTCP('::1', 8000)
> >>> to attach the protocol yourself.
> >>
> >> Thanks for your reply, Phil. So, I basically modified
> >> twisted/web/xmlrpc.py
> >> so that
> >> when it was calling connectTCP(), i substituted '::1' in place of
> >> self.host
> >> and yes the method is called successfully.
> >>
> >> I will consider your other hints and see if there is an easy way to work
> >> around this
> >> in my particular use case.
> >
> > I finally ended up doing this:
> 
> Just to point out this is obviously a pretty hackish way of doing it;
> for starters, getaddrinfo() is blocking, so you should use deferToThread
> at minimum.

Indeed it is very hackish. It is basically the first thing that helped me solve the problem.
> 
> You might want to look at:
> 
> http://twistedmatrix.com/trac/browser/tags/releases/twisted-13.2.0/twisted/internet/endpoints.py#L707
> 
> ...for inspiration.

Thanks, I will take a look and hopefully can modify my approach.

Best,
Amit.

-- 
Amit Saha <http://echorand.me>