OS: CentOS 7
lets create a docker yum repo.
# cd /etc/yum.repos.d/
# vim docker.repo
[dockerrepo]
name= Docker Repository
baseurl=https://yum.dockerproject.org/repo/main/centos/7/
enabled=1
gpgcheck=1
gpgkey=https://yum.dockerproject.org/gpg
###save & exit
# yum update
# yum install docker-engine -y
### in EL 6 disabled SELINUX or add chcon
# systemctl enable docker
# systemctl start...