-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 17/10/2014 9:29 a.m., Darren Spruell wrote: > On Thu, Oct 16, 2014 at 12:40 PM, Amos Jeffries > <squ...@treenet.co.nz> wrote: >> -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 >> >> On 17/10/2014 8:10 a.m., Darren Spruell wrote: >>> Had a use case to ask about, apologies if I missed in docs. Is >>> there a configuration that allows squid running as forward >>> proxy to add a custom response header containing the origin >>> server IP address that served the resource? Assuming no cache >>> hierarchy. >>> >>> In the event that the resource is served from cache, would be >>> interesting if squid were able to track the IP address from >>> which the cached resource was originally retrieved to include >>> in responses. In the event that's not possible, then the IP >>> address of the cache itself as well as an indication that the >>> resource was served from cache rather than an upstream origin. >>> >>> Most resources seem to cover including this information in the >>> access log, however I'm interested in having the data in the >>> HTTP response for this case. >>> >> >> IP address is not much useful in the response - any given machine >> has multiple of those and they are also shared between anycast >> servers or load balancers. > > Usefulness (utility) is in the eye of the beholder. :) > >> It is also a mistake to think of "the" server as being one >> machine. It is becomming extremely popular to use CDN services >> these days. CDN are reverse-proxy services in one form or >> another. So "the" server may be a chain of servers on some path >> through a server farm. > > In my case, those abstractions are not significant. The goal is > determining, for a client behind a forward proxy, can the proxy > simply inform the client of the IP address to which the proxy > connected to fetch the resource? The IP address is the key data > element for this case. Even with a CDN the IP address of the > frontend is fine. > >> 1) The Via header is closest to what you are seeking. In >> responses it contains each servers FQDN or an unique alias. It is >> supposed to contain a record of the whole chain of machines the >> message traversed. - The problem is that a lot of admin disable >> it or strip it out of the traffic. So you may get a proper chain >> or only what your proxy is adding, with no easy way to identify >> missing chain data. > > I view the Via header as similar to the Received header in SMTP. > In this case it's added by other proxies/caches, correct?
Thats a good analogy, but not quite. It MUST be added by all proxies including Squid. http://tools.ietf.org/html/rfc7230#section-5.7.1 paragraphs 3 and 5. In squid.conf simply remove any "via off" you may have. The default is to comply with the RFC "MUST send" criteria. Amos -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.22 (MingW32) iQEcBAEBAgAGBQJUQDBQAAoJELJo5wb/XPRjZqEH+QFbiYfRdd0t+ki+q6tN8TKQ I5XLxJSrF+yoYjbHb1neJgu1Y2wwfU2cEUgaG5fJhAHpVrdk4/0PdmU6K5aFFs/M 8FD3mDd+Ur/Vwapc55G9GpCis9fr747Yz5mDuqgrSA7JHyHKENUxS09umCvdiB0a VJmhxjhjOCZFc8Gj/qfvoz3orHwlNDY1ziMkCDIQW6pmwpi61yOust26faRq73yT TnYKNHCaK9R/ZZ3bQlGQCiWMTdbYcBdD3bxnlG5TaB4xxyTIOxWj1WGmJ3l4Ho8P gRbk2oNdMrNttXWCeGSt76XuymLY8oQ2RA4IToO1PQMO2QzsxfN1k+uE88pz+lk= =FC/N -----END PGP SIGNATURE----- _______________________________________________ squid-users mailing list squid-users@lists.squid-cache.org http://lists.squid-cache.org/listinfo/squid-users
