Docker registry mirroring failed, why?

the network of my site is in close network for internet, so * can not be reachable.
i construct docker registry to mirror, pushed ubuntu.tar image to registry by manually.
(by create topic policy, i worte xttp, but it’s http)

$ wget -qO- xttp://

ok, my registry has ubuntu image.

$ cat /etc/default/docker | grep DOCKER_OPTS

set DOCKER_OPTS, but it’s not connect to my mirror server like that.

$ sudo docker pull ubuntu:16.04
Error response from daemon: Get net/http: request canceled while waiting for connection (Client.Timeout exceeded while awaiting headers)

i just followed

why daemon try to connect *, instead of my xttp://