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Subject: Re: mod_proxy chaining with a .pac file
From: Ralf Mattes <rm@seid-online.de>
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In-Reply-To: <47978BEF.2030303@joe-lewis.com>
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Date: Wed, 23 Jan 2008 19:56:31 +0100
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On Wed, 2008-01-23 at 11:48 -0700, Joe Lewis wrote:
> Ralf Mattes wrote:
> > On Wed, 2008-01-23 at 11:12 -0700, Joe Lewis wrote:
> >   
> >> Giovanni Donelli wrote:
> >>     
> >>> I am trying to make Apache follow the same rules as the browser
> >>>   
> >>>       
> >> Realize that the browser doesn't get the configurations for each website 
> >> it visits, it only configures, then runs using the same configuration 
> >> for every website.
> >>     
> >
> > Realize that, since a .pac file is a ECMA-Script program, that
> > configuration can (and often will) be dynamic. The proxy needs to be
> > determined for each request.
> >
> >   
> >> That means it should be easy to create a simple module that has a single 
> >> configuration directive that points to the next proxy in the chain, 
> >> something like
> >>
> >> WPADConfiguration http://secondproxyserver.example.com/my-proxy-file.pac
> >>
> >> And then just configure mod_proxy, mod_proxy_http, and create a handler 
> >> that prefaces all URL's with the proxy: string, set the proxyreq setting 
> >> in the request_rec to an appropriate value, and return 1 to allow 
> >> mod_proxy to handle the rest of it.
> >>     
> >
> > No - that's too simple. The module needs to run the JS function for each
> > request and has to be able to dynamically set the proxy.
> >   
> 
> Indeed - I had completely forgotten about that.  Isn't there a 
> javascript library could be connected into, or should the module be 
> written in perl to use that?  I suppose parsing the file manually would 
> work.  But I don't like reinventing wheels.

There _IS_ a library (C and python(?) interface) - downloadable from the
google code link posted in the first message ... trivial to link into an
Apache module. AFAIK it uses the mozilla JS code.

 Cheers, RalfD

> Joe