最近在使用CentOS 7按照官方网站的文档安装docker时遇到了一个问题：

当我运行这一句时

sudo docker run hello-world

出现了bug：

net/http: TLS handshake timeout

解决方案：

配置镜像，修改 /etc/docker/daemon.json 文件，如果没有可以新建一个文件，然后加入以下的docker镜像地址：

{
  "registry-mirrors": [
    "https://dockerhub.azk8s.cn",
    "https://hub-mirror.c.163.com"
  ]
}

保存退出
然后重启docker

sudo systemctl restart docker

这里可以检查一下配置的镜像是否生效：

docker info

如果显示的配置信息的末尾部分出现如下字样，说明配置完成：

再次运行：

sudo docker run hello-world

出现以下的信息，证明问题已经解决了：

Hello from Docker!
This message shows that your installation appears to be working correctly.

To generate this message, Docker took the following steps:
 1. The Docker client contacted the Docker daemon.
 2. The Docker daemon pulled the "hello-world" image from the Docker Hub.
    (amd64)
 3. The Docker daemon created a new container from that image which runs the
    executable that produces the output you are currently reading.
 4. The Docker daemon streamed that output to the Docker client, which sent it
    to your terminal.

To try something more ambitious, you can run an Ubuntu container with:
 $ docker run -it ubuntu bash

Share images, automate workflows, and more with a free Docker ID:
 https://hub.docker.com/

For more examples and ideas, visit:
 https://docs.docker.com/get-started/