centos7.6 安装docker（Centos7安装Docker2020最新亲测可用，直接复制粘贴即可）

yum remove docker \
     docker-client \
     docker-client-latest \
     docker-common \
     docker-latest \
     docker-latest-logrotate \
     docker-logrotate \
     docker-engine

yum install -y yum-utils 

yum-config-manager \
 --add-repo \
 http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo

yum makecache fast

yum install docker-ce docker-ce-cli containerd.io

systemctl start docker

docker version

docker run hello-world