当我们使用docker下载镜像的时候常会遇见报错：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)等，如下图：

        解决方案如下(依次执行)：

sudo mkdir -p /etc/docker

sudo tee /etc/docker/daemon.json <<-'EOF'
{
    "registry-mirrors": [
        "https://docker.m.daocloud.io",
        "https://huecker.io",
        "https://dockerhub.timeweb.cloud",
        "https://noohub.ru"
    ]
}
EOF

sudo systemctl daemon-reload

sudo systemctl restart docker

        其实就是修改/etc/docker/daemon.json这个文件，把上面的json格式配置文件内容加进去，然后重启docker，再次测试拉去镜像就ok了：