Create a systemd drop-in directory for the docker service
$ sudo mkdir -p /etc/systemd/system/docker.service.d
Add proxy configuration into /etc/systemd/system/docker.service.d/http-proxy.conf
(create if not exist)
[Service]
Environment="HTTP_PROXY=<your_proxy>"
Environment="HTTPS_PROXY=<your_proxy>/"
Environment="NO_PROXY=localhost,127.0.0.1"
Flush change and restart service
$ sudo systemctl daemon-reload
$ sudo systemctl restart docker