On an Ubuntu 12.04 server, with squid-deb-proxy installed, client machines on the network will properly contact the server when installing packages, but squid never caches packages.
From /var/log/squid-deb-proxy/access.log:
1368371692.721 485 192.168.1.220 TCP_MISS/200 20304 GET http://us.archive.ubuntu.com/ubuntu/pool/universe/c/cowsay/cowsay_3.03+dfsg1-3_all.deb - DIRECT/91.189.91.13 application/x-debian-package
1368371721.534 264 192.168.1.210 TCP_MISS/200 20304 GET http://us.archive.ubuntu.com/ubuntu/pool/universe/c/cowsay/cowsay_3.03+dfsg1-3_all.deb - DIRECT/91.189.91.13 application/x-debian-package
Both 192.168.1.220 & .210 contacted the server (.210 is the server, but also has squid-deb-proxy-client installed), but .210 received TCP_MISS/200, instead of being served the cached package.
From /var/log/squid-deb-proxy/store.log:
1368371692.721 RELEASE -1 FFFFFFFF 1255C76AE7E24BA02B4ABB6A3E4AB535 200 1368371672 1293023126 -1 application/x-debian-package 19904/19904 GET http://us.archive.ubuntu.com/ubuntu/pool/universe/c/cowsay/cowsay_3.03+dfsg1-3_all.deb
1368371721.534 RELEASE -1 FFFFFFFF 3534FA3574ED95020E8C960C75129676 200 1368371700 1293023126 -1 application/x-debian-package 19904/19904 GET http://us.archive.ubuntu.com/ubuntu/pool/universe/c/cowsay/cowsay_3.03+dfsg1-3_all.deb
If I'm reading the store.log right, squid cached two copies of the exact same file. (I used cowsay to test; much larger files, like linux-headers-* also were never cached.)
The only changes from the default squid-deb-proxy.conf were to enable mirrors:
81,82c81,82
< http_access deny !to_ubuntu_mirrors
< #http_access allow !to_ubuntu_mirrors
---
> #http_access deny !to_ubuntu_mirrors
> http_access allow !to_ubuntu_mirrors
86,87c86,87
< cache deny !to_ubuntu_mirrors
< #cache allow !to_ubuntu_mirrors
---
> #cache deny !to_ubuntu_mirrors
> cache allow !to_ubuntu_mirrors
Lastly, the only errors I have seen in squid-specific logs are:
$ sudo cat /var/log/upstart/squid-deb-proxy.log.1
2013/05/09 09:27:05| Warning: empty ACL: acl blockedpkgs urlpath_regex "/etc/squid-deb-proxy/autogenerated/pkg-blacklist-regexp.acl"
2013/05/09 09:27:05| WARNING: (B) '::/0' is a subnetwork of (A) '::/0'
2013/05/09 09:27:05| WARNING: because of this '::/0' is ignored to keep splay tree searching predictable
2013/05/09 09:27:05| WARNING: You should probably remove '::/0' from the ACL named 'all'
Given that the clients are correctly contacting the server's proxy, why won't squid cache & return the packages?