Install Docker on CentOS 7.X

#!/bin/bash
#
# Docker on CentOS
#
# Check Prerequisites
#
# Check CentOS 7.X
cat /etc/issue
echo "Make sure you see CentOS 7 or terminate the script with Ctrl-C"
sleep 20
#
# Check 64-bit
uname –a
echo "Make sure you see 64 bit or terminate the script with Ctrl-C"
sleep 20
#
# Check kernel > 3.10
cat /proc/version
uname -r
echo "Make sure you see Kernel version 3.10 or higher or terminate the script with Ctrl-C"
sleep 20
#
# Check root privileges
if [[ $EUID -ne 0 ]]; then
   echo "This script must be run as root"
   exit 1
fi
#
# Set SELinux DISABLED for future purposes
sed -i 's!SELINUX=enabled!SELINUX=disabled!g' /etc/selinux/config
#
# Check fully update system
yum update -y
#
# Add the yum repo.
cat >/etc/yum.repos.d/docker.repo <<-EOF
[dockerrepo]
name=Docker Repository
baseurl=https://yum.dockerproject.org/repo/main/centos/7
enabled=1
gpgcheck=1
gpgkey=https://yum.dockerproject.org/gpg
EOF
#
# fully update system (again)
yum update -y
#
# Install the Docker package.
yum install docker-engine -y
#
# Start the Docker daemon.
service docker start
#
# Start the docker daemon at boot
chkconfig docker on
#
# Verify docker is installed correctly by running a test image in a container.
docker run hello-world
#
# To try something more ambitious, you can run an Ubuntu container with:
docker run -it ubuntu bash