阿里云的VPS，安装的是镜像市场中的Docker运行环境（Ubuntu 64位）系统，用docker pull镜像的时候会报错，具体错误如下：
Unable to find image ‘busybox’ locally
Pulling repository registry
2016/08/24 16:29:53 Could not reach any registry endpoint
docker version 查看到的信息如下：
Client version: 1.2.0
Client API version: 1.14
Go version (client): go1.3.1
Git commit (client): fa7b24f
OS/Arch (client): linux/amd64
Server version: 1.2.0
Server API version: 1.14
Go version (server): go1.3.1
Git commit (server): fa7b24f
针对此错误的解决方法如下：
1，需要升级docker，具体命令如下：
sudo apt-get install docker.io
2，不过阿里的这个镜像源有点问题，升级的时候部分源是404，会报错。需要修改/etc/apt/sources.list文件，修改为如下内容：
deb http://mirrors.aliyun.com/ubuntu/ trusty main multiverse restricted universe
deb http://mirrors.aliyun.com/ubuntu/ trusty-backports main multiverse restricted universe
deb http://mirrors.aliyun.com/ubuntu/ trusty-proposed main multiverse restricted universe
deb http://mirrors.aliyun.com/ubuntu/ trusty-security main multiverse restricted universe
deb http://mirrors.aliyun.com/ubuntu/ trusty-updates main multiverse restricted universe
deb-src http://mirrors.aliyun.com/ubuntu/ trusty main multiverse restricted universe
deb-src http://mirrors.aliyun.com/ubuntu/ trusty-backports main multiverse restricted universe
deb-src http://mirrors.aliyun.com/ubuntu/ trusty-proposed main multiverse restricted universe
deb-src http://mirrors.aliyun.com/ubuntu/ trusty-security main multiverse restricted universe
deb-src http://mirrors.aliyun.com/ubuntu/ trusty-updates main multiverse restricted universe
3，apt-get clean && apt-get update
4，然后继续sudo apt-get install docker.io
升级完成之后就可以成功解决前文中提到的错误。