为docker服务创建一个systemd的插入目录：

 [root@localhost ~]# mkdir -p /etc/systemd/system/docker.service.d

创建文件/etc/systemd/system/docker.service.d/http-proxy.conf， 添加HTTP_PROXY和HTTPS_PROXY环境变量：

 [root@localhost ~]# vim /etc/systemd/system/docker.service.d/http-proxy.conf
 [Service]
 Environment="HTTP_PROXY=127.0.0.1:8889"
 Environment="HTTPS_PROXY=127.0.0.1:8889"

刷新更改，重新启动Docker

 [root@localhost ~]# systemctl daemon-reload
 [root@localhost ~]# systemctl restart docker

验证更改

 [root@localhost ~]# systemctl show --property=Environment docker
 Environment=HTTP_PROXY=127.0.0.1:8889 HTTPS_PROXY=127.0.0.1:8889