因为网络原因，国内的开发者从docker hub下载镜像，经常会出现下载中断的问题。查询资料了解到可以使用国内的容器Hub加速服务解决这个问题，其本质就是更改pull优先级较高的服务器为国内的站点，下面分享操作步骤。
加速地址
系统环境
[root@iZ51hzu4zdjgpnZ home]# cat /etc/redhat-release
CentOS Linux release 7.4.1708 (Core)
[root@iZ51hzu4zdjgpnZ home]# docker version
Client:
Version: 1.13.1
API version: 1.26
Package version: docker-1.13.1-74.git6e3bb8e.el7.centos.x86_64
Go version: go1.9.4
Git commit: 6e3bb8e/1.13.1
Built: Tue Aug 21 15:23:37 2018
OS/Arch: linux/amd64
Server:
Version: 1.13.1
API version: 1.26 (minimum version 1.12)
Package version: docker-1.13.1-74.git6e3bb8e.el7.centos.x86_64
Go version: go1.9.4
Git commit: 6e3bb8e/1.13.1
Built: Tue Aug 21 15:23:37 2018
OS/Arch: linux/amd64
Experimental: false
DaoCloud加速
访问DaoCloud 配置指引，根据指引DaoCloud提供一键配置脚本。
但直接复制脚本运行后，重启失败
[root@iZ51hzu4zdjgpnZ home]# service docker restart
Redirecting to /bin/systemctl restart docker.service
Job for docker.service failed because the control process exited with error code. See "systemctl status docker.service" and "journalctl -xe" for details.
检查后发现，/etc/docker/daemon.json 文件的json格式存在问题，直接手动修改，修改为
{
"registry-mirrors": [
"http://8882ac6a.m.daocloud.io"
],
"insecure-registries": []
}
手动修改后重启服务器
[root@iZ51hzu4zdjgpnZ home]# service docker restart
Redirecting to /bin/systemctl restart docker.service
重启成功后，就可以愉快的下载镜像啦~
