$ uname -r
3.10.0-229.el7.x86_64

$ sudo yum update

$ sudo tee /etc/yum.repos.d/docker.repo <<-'EOF'
[dockerrepo]
name=Docker Repository
baseurl=https://yum.dockerproject.org/repo/main/centos/$releasever/
enabled=1
gpgcheck=1
gpgkey=https://yum.dockerproject.org/gpg
EOF

$ sudo yum install docker-engine

$ sudo service docker start

$ sudo docker run hello-world
Unable to find image 'hello-world:latest' locallylatest: Pulling from hello-worlda8219747be10: Pull complete91c95931e552: Already existshello-world:latest: The image you are pulling has been verified. Important: image verification is a tech preview feature and should not be relied on to provide security.Digest: sha256:aa03e5d0d5553b4c3473e89c8619cf79df368babd1.7.1cf5daeb82aab55838dStatus: Downloaded newer image for hello-world:latestHello from Docker.This message shows that your installation appears to be working correctly.To generate this message, Docker took the following steps:1. The Docker client contacted the Docker daemon.2. The Docker daemon pulled the "hello-world" image from the Docker Hub.(Assuming it was not already locally available.)3. The Docker daemon created a new container from that image which runs theexecutable that produces the output you are currently reading.4. The Docker daemon streamed that output to the Docker client, which sent itto your terminal.To try something more ambitious, you can run an Ubuntu container with:$ docker run -it ubuntu bashFor more examples and ideas, visit:http://docs.docker.com/userguide/

$ sudo chkconfig docker on

$ yum list installed | grep docker
yum list installed | grep docker
docker-engine.x86_64   1.7.1-1.el7 @/docker-engine-1.7.1-1.el7.x86_64.rpm

$ sudo yum - y remove docker-engine.x86_64

$ rum -rf /var/lib/docker