[Zope-dev] The Zope CGI executable, rewriting URLs on IIS

[Brian Lloyd]

> What exactly does the Win32 Zope CGI executable _do_?
> 
> I mean the one that comes with Zope and is stored as
> <installationname>.exe (eg., website.exe) under the web 
> server directory
> you selected as part of the installation sequence. I assume it
> communicates with the Zope service, but how? Using HTTP?

Basically, the windows service/cgi.exe stuff is a holdover from the
past, when PCGI didn't work on windows. The win32 service listens
on a named pipe for connections from the cgi executable - the two
communicate using the PCGI protocol. If you'd like, I can probably
send you the service/cgi code - I'm sure that the powers that be
here would love to see an ISAPI version of the cgi executable.
Over time, I expect PCGI to obsolete this system, but there just
haven't been enough resources to work on this lately :( While I'm
pretty sure PCGI actually works now on win32, there is some work
to do rolling it into the installation, documentation, etc.



> 
> The reason I ask is that I'd like to emulate the behaviour in an ISAPI
> filter DLL. The cool thing about filters is that your filter can grab
> all requests and preprocess them any way it likes.
> 
> I have already written a filter which rewrites URLs so that eg.,
> "/QuickStart" becomes "/cgi-bin/zope.exe/QuickStart", and this works
> perfectly, except that Zope always forces <base href="..."> in
> documents, so only the initial document you refer to accepts this URL
> okay. All others go to the zope.exe URL. Even if I patch 
> HTTPResponse.py
> to _not_ do this (which probably has major consequences for some apps,
> though), Zope often uses SCRIPT_NAME, PATH_INFO etc. for a 
> lot of URLs,
> and my filter cannot modify these variables to reflect the "fake" URL.
> (Anybody with me so far?)
> 
> One solution would be to force Zope to always use a specific base URL,
> but I don't know even how to do this. Anyway I _presume_ that the CGI
> executable actually sends the path information to Zope, and 
> so I need a
> little bit more information. Anyone?

I tried writing a (rather simple) filter once, but never really
tried to tackle this problem. I assume that if you had an ISAPI
thing calling the service though, it could probably munge the 
request a bit to do the right thing.



Brian Lloyd        brian@digicool.com
Software Engineer  540.371.6909              
Digital Creations  http://www.digicool.com