环境： 阿里云服务器 CENTOS7.6   64位  　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　

[root@localhost ~]# uname -a
Linux localhost 3.10.0-1127.19.1.el7.x86_64 #1 SMP Tue Aug 25 17:23:54 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux

1、安装docker环境依赖

[root@localhost ~]# yum install -y yum-utils device-mapper-persistent-data lvm2

2、配置国内docker的yum源 

网易163yum源，安装方法查看：http://mirrors.163.com/.help/
中科大yum源，安装方法查看：https://lug.ustc.edu.cn/wiki/mirrors/help
搜狐yum源，安装方法查看: http://mirrors.sohu.com/help/
阿里云yum源，安装方法查看: https://mirrors.aliyun.com/
清华yum源，安装方法查看: https://mirrors.tuna.tsinghua.edu.cn/
浙大yum源，安装方法查看: http://mirrors.zju.edu.cn/
科大yum源，安装方法查看: http://centos.ustc.edu.cn/

方法一：
a.备份yum默认仓库文件
[root@localhost ~]# cd /etc/yum.repos.d   ---进入仓库目录 

[root@localhost ~]# mv CentOS-Base.repo CentOS-Base.repo.backup ---备份默认源文件 

b.下载国内仓库源文件

[root@localhost ~]# wget -O ./CentOS-Base.repo http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo

# 下载后执行以下两条命令 

[root@localhost ~]# yum clean all ---清空缓存 

[root@localhost ~]# yum makecache ---生成缓存

方法二：

[root@localhost ~]# yum-config-manager --add-repo http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo

3、安装docker-ce：

[root@localhost ~]# yum install docker-ce docker-ce-cli containerd.io -y

docker-ce-cli 是docker命令行工具包，containerd.io 是容器接口相关包
yun info 软件包的命令，可以查看一个包的具体作用

[root@localhost ~]# yum info docker-ce docker-ce-cli containerd.io
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
Installed Packages
Name : containerd.io
...
Description : containerd is an industry-standard container runtime with an emphasis on
: simplicity, robustness and portability. It is available as a daemon for Linux
: and Windows, which can manage the complete container lifecycle of its host
: system: image transfer and storage, container execution and supervision,
: low-level storage and network attachments, etc.

Name : docker-ce
....
Description : Docker is a product for you to build, ship and run any application as a
: lightweight container.
: 
: Docker containers are both hardware-agnostic and platform-agnostic. This means
: they can run anywhere, from your laptop to the largest cloud compute instance and
: everything in between - and they don't require you to use a particular
: language, framework or packaging system. That makes them great building blocks
: for deploying and scaling web apps, databases, and backend services without
: depending on a particular stack or provider.

Name : docker-ce-cli
...
Description : Docker is is a product for you to build, ship and run any application as a
: lightweight container.
: 
: Docker containers are both hardware-agnostic and platform-agnostic. This means
: they can run anywhere, from your laptop to the largest cloud compute instance and
: everything in between - and they don't require you to use a particular
: language, framework or packaging system. That makes them great building blocks
: for deploying and scaling web apps, databases, and backend services without
: depending on a particular stack or provider.

4、启动并且设置开机自启

[root@localhost ~]# systemctl start docker && systemctl enable docker

5、显示 Docker 版本信息

[root@localhost ~]# docker version
Client: Docker Engine - Community
Version: 20.10.12

Server: Docker Engine - Community
Engine:
Version: 20.10.12
API version: 1.41 (minimum version 1.12)
Go version: go1.16.12

6、查看 docker 信息

[root@localhost ~]# docker info #
Client:
...

Server:
...
Server Version: 20.10.12
...
Plugins: 
...
Docker Root Dir: /var/lib/docker ##默认的docker的家目录
...
Live Restore Enabled: false 

至此，docker环境搭建完成！