avahi service discovery failure when bind installed causes apt proxy setting from apt.conf to be ignored

[Grant Walters]

Binary package hint: apt

I am using apt-cacher so I have put Acquire::http { Proxy "http://localhost:3142"; }; into my apt.conf file.
Yesterday I downloaded bind9 which has installed itself and started. I haven't had time yet to configure for my local domain but I noticed that when I did an apt-get update, it wasn't going through apt-cacher.
I also downloaded squid-deb-proxy to have a look at (which I haven't configured).
apt-get update spat out a "service_browser failed: DNS failure: NXDOMAIN" error.
I shut down bind, commented out #Acquire::http::ProxyAutoDetect "/usr/share/squid-deb-proxy-client/apt-avahi-discover"; from the 30autoproxy file and things went back to normal.

While I appreciate that I have some configuration work to do. Whatever is the causes of the failure message, whether it be bind not configued or squid-deb-proxy not configured, the original Proxy line in the apt.conf file should be observed?

[Torsten Spindler (tspindler)]

Thank you for taking the time to report this bug and helping to make Ubuntu better.

For clarification, your bug is about apt being more resilient towards configuration errors in other components, like squid-deb-proxy and apt-cacher?

[Grant Walters (grunter)]

Yes, sort of :-) I'm still working out where everything is on Ubuntu nowadays, so it can be a pain when something just stops working. In this case, I think the fault lies with the squid-deb-proxy failure rather than with apt or bind.
I would assume that the initial Proxy server entry would have been collected without trouble initially by apt and then the reference has been reset by squid-deb-proxy but I'm not sure.
The old rule of leaving the environment the way it was if you aren't successful should be applied here.
If a proxy exists when the /usr/share/squid-deb-proxy-client/apt-avahi-discover code runs, then it should still exist if the apt-avahi-discover code fails. The same should apply to any other code running.
Sorry I can't be of more help at the moment. Service discovery/zeroconf is on my list for the next few weeks.

[Torsten Spindler (tspindler)]

Unfortunately we have only a few developers working actively on apt and they are quite busy with critical issues. will mark this bug as a wishlist item, hoping that it will be eventually picked up. Thanks again for reporting the issue!