On 28/03/2013 12:28 p.m., Alex Stahl wrote:
Hiya Squid Users - So I'm trying to configure Squid as a reverse
proxy, listening on port 80, in front of two web servers. One web
server runs on the localhost and listens on port 81 and contains a
subset of all website content. Then the second web server is a remote
box, listening on port 80, with a full set of all content.
What I'd like Squid to do is act as a single front-end for these
servers. A request comes in, and if it's a cache miss, it should
first ask the localhost web server if it can satisfy the request. If
so, it serves it up. If not, it should forward it on to the second
web server.
Which squid vesion? the presence or absence of vhost settings depends on it.
Following the guide here:
http://wiki.squid-cache.org/ConfigExamples/Reverse/MultipleWebservers,
I've come up with the following config:
http_port 80 accel defaultsite=localhost
Problem #1 Use the public FQDN name in defaultsite=.
The above config will make some URLs handled by Squid all be
http://localhost/... which is NOT a good thing when those URLs are sent
out to the client.
cache_peer localhost parent 81 0 originserver name=local
cache_peer example.com parent 80 0 originserver name=remote
acl request dstdomain localhost
cache_peer_access local allow request
cache_peer_access remote allow request
(I have other ACLs unrelated to this config, such as allowing http
requests on port 80).
The problem I run into is that a miss on the localhost web server (an
HTTP 404) isn't properly forwarded on to the remote server - squid
only ever tries a single parent. If I remove the localhost peer, the
request is properly forwarded, and I get back the expected HTTP 200.
What am I missing in my config to make it do that?
404 means "does not exist". How is Squid to know that the localhost peer
was lying and some other peer does have the object?
* Fix the "defaultsite=localhost" problem
* Add "vhost" to your http_port line to make Squid aware of what domains
requests are for.
* alter your "request" ACL into different ACLs which match against
requests destined to each server. Such that only the server where the
request can come from is contacted.
Amos
