mkdir -p /etc/systemd/system/docker.service.d
vi /etc/systemd/system/docker.service.d/http-proxy.conf
加入内容：
[Service]
Environment="HTTP_PROXY=http://proxy-addr:port/"
Environment="HTTPS_PROXY=http://proxy-addr:port/"
Environment="NO_PROXY=localhost,127.0.0.1"
systemctl show --property=Environment docker
systemctl daemon-reload
systemctl restart docker