docker: unrecognized service

解决方法：

yum remove docker

yum remove docker-selinux

vi /etc/yum.repos.d/docker.repo

[dockerrepo]

name=Docker Repository

baseurl=https://yum.dockerproject.org/repo/main/centos/$releasever/

enabled=1

gpgcheck=1

gpgkey=https://yum.dockerproject.org/gpg

yum install docker-engine

service docker start