[Twisted-Python] Problem with XMLRPC resource wrapped with guard basic auth

[exarkun at twistedmatrix.com]

On 12:00 am, asset at impactdamage.com wrote:
>Using the current trunk r27366 (which is after #4014 fixed a related
>issue), I am having trouble with an implementation of web.guard wrapped
>XMLRPC.  This is a new test implementation to expose both a soap and 
>xmlrpc
>interface.  SOAP works, but xmlrpc throws UnsupportedMethod POST.

I think you're being tricked by the confusing way in which this 
exception is displayed and by a slight implementation difference (and 
indeed externally visible behavioral difference) between XMLRPC and 
SOAPPublisher.

SOAPPublisher defines "render" and no other render methods.  So it will 
accept any request method and treat it the same way.  It will never 
raise UnsupportedMethod.

XMLRPC, on the other hand, defines "render_POST" and no other render 
methods, so it will only accept POST requests.  For any other request, 
it will raise UnsupportedMethod and create that exception with a tuple 
of which methods it does allow.  ('POST',) in this case.

The exception I see when I approach this server at /rpc2 with my web 
browser (which is the only thing I've tried, because it's too much work 
to put together a real xml-rpc client that supports basic auth) is just 
what I'd expect.  The browser issues a GET, the XMLRPC resource rejects 
this, indicating it only accepts POSTs.

It may be worth improving the way UnsupportedMethod exceptions are 
stringified to make it more clear what's going on.  Or, if this doesn't 
actually explain your problem, feel free to point that out and provide 
more details about how the client you're using behaves.

Jean-Paul