Reverse Proxy with HTTP/1.1 Domain Based Virtual Host Support
Warning: Any example presented here is provided "as-is" with no support or guarantee of suitability. If you have any further questions about these examples please email the squid-users mailing list.
This configuration MUST appear at the top of squid.conf above any other forward-proxy configuration (http_access etc). Otherwise the standard proxy access rules block some people viewing the accelerated site.
http_port 80 accel defaultsite=your.main.website.name vhost
accel tells Squid to handle requests coming in this port as if it was a Web Server
defaultsite=X tells Squid to assume the domain X is wanted.
When both defaultsite and vhost is specified, defaultsite specifies the domain name old HTTP/1.0 clients not sending a Host header should be sent to. Squid will run fine if you only use vhost, but there is still some software out there not sending Host headers so it's recommended to specify defaultsite as well. If defaultsite is not specified those clients will get an "Invalid request" error.
Next, you need to tell Squid where to find the real web server:
cache_peer backend.webserver.ip.or.dnsname parent 80 0 no-query originserver name=myAccel
And finally you need to set up access controls to allow access to your site without pushing other web requests to your web server.
acl our_sites dstdomain your.main.website.name http_access allow our_sites cache_peer_access myAccel allow our_sites cache_peer_access myAccel deny all
You should now be able to start Squid and it will serve requests as a HTTP server.
Testing and Live
Testing of reverse-proxies should be done with Squid configured properly as it would be used in production. But the public DNS setting not pointing at it. The /etc/hosts file of a test machine can be altered to send test requests to the squid IP instead of the live webserver.
When that testing works, public DNS can be updated to send public requests to the Squid proxy instead of the master web server and Acceleration will begin immediately.