yum install docker-io
service docker start
chkconfig docker on
docker images
遇到问题：
service docker status
docker dead but pid file exists
解决方法：
yum install device-mapper-event-libs
yum install docker-io
service docker start
chkconfig docker on
docker images
遇到问题：
service docker status
docker dead but pid file exists
解决方法：
yum install device-mapper-event-libs
