编辑Docker配置文件/usr/lib/systemd/system/docker.service，添加以下内容

[Service]
Environment="HTTP_PROXY=http://192.168.126.1:7890"
Environment="HTTPS_PROXY=http://192.168.126.1:7890"

重启Docker服务

systemctl daemon-reload
systemctl restart docker

测试访问代理端口

telnet 192.168.126.1 7890

查看代理配置

docker info