r778 - in trunk/varnish-cache: bin/varnishd include lib/libvcl

[Dag-Erling Smørgrav]

des at projects.linpro.no writes:
> Log:
> Add support for using separate backends for separate virtual hosts:
>
>  - remove the obj.backend variable, which is not connected to anything.
>  - define a req.backend variable and implement l/r functions for it
>  - complete / correct support for setting / comparing backend values

With this patch, I have successfully proxied VG and Aftenposten
through the same Varnish instance using the following VCL code:

> backend vg {
>         set backend.host = "leonora.vg.no";
>         set backend.port = "80";
> }
>
> backend tanta {
>         set backend.host = "80.91.37.210"; /* www.aftenposten.no */
>         set backend.port = "80";
> }
>
> sub vcl_recv {
>         if (req.http.host ~ "^(www\\.)?vg\\.no$") {
>                 /* set req.http.host = "www.vg.no"; */
>                 set req.backend = vg;
>         } elsif (req.http.host ~ "^(www\\.)?aftenposten\\.no$") {
>                 /* set req.http.host = "www.aftenposten.no"; */
>                 set req.backend = tanta;
>         } else {
>                 error 404;
>         }
> }

Note that this only works if the client provides a valid Host: header.
What I want to do in the long run is:

 - define HTTP_HDR_HOST and the corresponding req.host variable to be
   used instead of req.http.host.

 - add code to cache_http.c to dissect and normalize the request URL,
   and set the initial value of req.host based on the host part of the
   request URL and / or the Host: header

 - make req.host and req.url writable so vcl_recv can perform further
   normalization if needed (e.g. rewrite vg.no to www.vg.no)

DES
-- 
Dag-Erling Smørgrav
Senior Software Developer
Linpro AS - www.linpro.no