url_rewrite_program by squid-cache really redirects the URL. In other words, the end-user gets a response back that says "redirectted page from foo to bar", and then the user makes another request to the redirected address. I don't want this.
what I want to achieve is similar to apache's mod_rewrite. I want an abselutely transparent rewriting mechanism. So that the user requests for a spefific content, and he gets it as a response (regardless of his initial requested URL) without any HTTP redirection.
the reason I want to avoid redirection via http is because I don't want the end-user to see internal application structures. For example, he requests "application1.foo.com", and he gets content of a URL that's much lengthier. So if the end-user bookmarks it, he bookmarks my clean little URL (application1.foo.com", this is good to keep users away from such details, it eventually gives them a uniform URL for the service even if I change it in the future. For example, I might map application1.foo.com to badprovider.com/path/to/file.php initially, and then change it to goodprovider.com/file.php and the user won't notice that. The advantage is, for example, end-user bookmarks would remain correct, as well as regulating their behaviour in a more guided manner.
Did you try setting squid as a reverse proxy with the 'accel' mode ? It worked for me:
acl all src all http_port 3128 accel vhost cache_peer 127.0.0.1 parent 80 0 no-query originserver name=myAccel acl our_sites dstdomain your_domain.net http_access allow our_sites http_access deny all cache_peer_access myAccel allow our_sites cache_peer_access myAccel deny all negative_ttl 0 access_log /var/log/squid/access.log squid hosts_file /etc/hosts coredump_dir /var/spool/squid
your_domain.net is the domain you want to redirect