原文：https://www.cnblogs.com/sdgtxuyong/p/18647915
https://www.cnblogs.com/OneSeting/p/18532166

docker 换源，解决连接不上的问题。
编辑以下文件，不存在则创建：

vim /etc/docker/daemon.json 

{"registry-mirrors" : ["https://docker.registry.cyou",
"https://docker-cf.registry.cyou",
"https://dockercf.jsdelivr.fyi",
"https://docker.jsdelivr.fyi",
"https://dockertest.jsdelivr.fyi",
"https://mirror.aliyuncs.com",
"https://dockerproxy.com",
"https://mirror.baidubce.com",
"https://docker.m.daocloud.io",
"https://docker.nju.edu.cn",
"https://docker.mirrors.sjtug.sjtu.edu.cn",
"https://docker.mirrors.ustc.edu.cn",
"https://mirror.iscas.ac.cn",
"https://docker.rainbond.cc",
"https://do.nark.eu.org",
"https://dc.j8.work",
"https://dockerproxy.com",
"https://gst6rzl9.mirror.aliyuncs.com",
"https://registry.docker-cn.com",
"http://hub-mirror.c.163.com",
"http://mirrors.ustc.edu.cn/",
"https://mirrors.tuna.tsinghua.edu.cn/",
"http://mirrors.sohu.com/"
],"insecure-registries" : ["registry.docker-cn.com","docker.mirrors.ustc.edu.cn"],
"debug": true,
"experimental": false
}

编辑完重启服务：

sudo systemctl daemon-reload
sudo systemctl start docker