报错信息：

 docker pull centos
Using default tag: latest
Error response from daemon: Get "https://registry-1.docker.io/v2/": net/http: request canceled while waiting for connection (Client.Timeout exceeded while awaiting headers)

问题：配置的阿里加速镜像现在停用失效，导致网络无法访问

解决措施：

[root@localhost ~]# tee /etc/docker/daemon.json <<-'EOF'
{
    "registry-mirrors": [
        "http://hub-mirror.c.163.com",
        "https://mirrors.tuna.tsinghua.edu.cn",
        "http://mirrors.sohu.com",
        "https://ustc-edu-cn.mirror.aliyuncs.com",
        "https://ccr.ccs.tencentyun.com",
        "https://docker.m.daocloud.io",
        "https://docker.awsl9527.cn"
    ]
}
EOF
 

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

解决后重新获取镜像

[root@localhost ~]# docker pull centos
Using default tag: latest
latest: Pulling from library/centos
a1d0c7532777: Pull complete
Digest: sha256:a27fd8080b517143cbbbab9dfb7c8571c40d67d534bbdee55bd6c473f432b177
Status: Downloaded newer image for centos:latest
docker.io/library/centos:latest
[root@localhost ~]# docker images
REPOSITORY   TAG       IMAGE ID       CREATED       SIZE
centos       latest    5d0da3dc9764   3 years ago   231MB