docker use --- 1: install docker under centos7

# 1: Install wget 
sudo yum -i install yum 
# 2: Update yum to the latest version 
sudo yum update 
# 3: Uninstall the old version 
sudo yum remove docker docker-common docker-selinux docker-engine 
# 4: Install the dependent package 
sudo yum install -y yum-utils device-mapper-persistent-data lvm2 
# 5: set yum source 
sudo yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo 
# 6: View version 
sudo yum list docker-ce --showduplicates | sort -r 
# 7: Install docker docker-ce to install the latest version by default, you can also install 
sudo yum install docker-ce by version name 
# 8: Start docker 
systemctl start docker 
# 9: Set the 
systemctl enable docker at boot 
# 10: View the docker status 
docker version