Assuming /etc/default/lxc is sourced, how about integrating this directly in it:
# Is there a local apt-proxy/cacher available ? eval $(apt-config shell MIRROR Acquire::http::Proxy) -- You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to lxc in Ubuntu. https://bugs.launchpad.net/bugs/1081786 Title: lxc-create doesn't take advantage of the apt proxy To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/lxc/+bug/1081786/+subscriptions -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs