Comment 8 for bug 1180355

Proxy configuration

In most setups, you’ll want the LXD daemon to fetch images from remote servers.

If you are in an environment where you must go through a HTTP(s) proxy to reach the outside world, you’ll want to set a few configuration keys or alternatively make sure that the standard PROXY environment variables are set in the daemon’s environment.

lxc config set core.proxy_http http://squid01.internal:3128
lxc config set core.proxy_https http://squid01.internal:3128
lxc config set core.proxy_ignore_hosts image-server.local
With those, all transfers initiated by LXD will use the squid01.internal HTTP proxy, except for traffic to the server at image-server.local

Source : https://www.stgraber.org/2016/03/15/lxd-2-0-installing-and-configuring-lxd-212/