一.确认CentOS 版本
　　cat /etc/redhat-release
　　
二.yum安装gcc相关插件
　　2.1 yum -y install gcc
　
2.2 yum -y install gcc-c++

三.安装需要的软件包
yum install -y yum-utils device-mapper-persistent-data lvm2

四.设置stable镜像仓库
yum-config-manager --add-repo https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo (建议使用这个)
或
yum-config-manager --add-repo http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo

五.更新yum软件包索引
yum makecache fast

六.安装docker ce
6.1
yum -y install docker-ce

如果遇到以下错误

报错
Problem: package docker-ce-3:20.10.0-3.el7.x86_64 requires containerd.io >= 1.4.1, but none of the providers can be installed

强制安装1.4.3-3.1版本的包
dnf install https://download.docker.com/linux/centos/8/x86_64/stable/Packages/containerd.io-1.4.3-3.1.el8.x86_64.rpm

安装1.4.3-3.1包 遇到以下报错的话
Error:
Problem: problem with installed package podman-2.2.1-7.module_el8.3.0+699+d61d9c41.x86_64

• package podman-2.2.1-7.module_el8.3.0+699+d61d9c41.x86_64 requires runc >= 1.0.0-57, but none of the providers can be installed
• package containerd.io-1.4.3-3.1.el8.x86_64 conflicts with runc provided by runc-1.0.0-70.rc92.module_el8.3.0+699+d61d9c41.x86_64
• package containerd.io-1.4.3-3.1.el8.x86_64 obsoletes runc provided by runc-1.0.0-70.rc92.module_el8.3.0+699+d61d9c41.x86_64
• package docker-ce-3:20.10.4-3.el8.x86_64 requires containerd.io >= 1.4.1, but none of the providers can be installed
• cannot install the best candidate for the job
• package runc-1.0.0-64.rc10.module_el8.3.0+479+69e2ae26.x86_64 is filtered out by modular filtering

则执行以下命令 ： yum erase podman buildah
遇到
期间会有确认提示 Is this ok [y/N]: ，输入 y 回车即可，然后继续等待下载安装完成。

以上报错成功解决之后，重新执行 ：yum -y install docker-ce

七.设置开机自启Docker并启动Docker
systemctl enable docker.service

systemctl start docker.service

八.查看docer 版本
　　docker version

出现以下问题，恭喜安装成功