报错：
docker: error pulling image configuration: Get https://production.cloudflare.docker.com/registry-v2/docker/registry/v2/blobs/sha256/a4/a4fdfd462add8e63749aa08ff0044b13d342a042965f1ec6744586cda10dfce9/data?verify=1591601228-BB%2FSFfmL4YVZUUoBsVmYZxIZym4%3D: dial tcp 104.18.121.25:443: i/o timeout.
解决：
$ vim /etc/docker/daemon.json
{
"registry-mirrors": ["https://registry.docker-cn.com","https://nrbewqda.mirror.aliyuncs.com","https://dmmxhzvq.mirror.aliyuncs.com"]
}
$ systemctl daemon-reload && systemctl restart docker
然后再来pull镜像即可