1.官网中文安装参考手册
https://docs.docker-cn.com/engine/installation/linux/docker-ce/centos/#prerequisites

2、yum安装gcc相关

1）CentOS7能上外网

2）安装gcc

[root@localhost ~]# yum -y install gcc

3）安装gcc-c++

[root@localhost ~]# yum -y install gcc-c++

4)验证gcc是否安装成功

[root@localhost ~]#gcc -v

出现如下图中画红色框的版本号说明gcc安装成功

3、如果之前安装过docker，卸载旧版本

[root@localhost ~]# yum remove docker \
>                       docker-client \
>                       docker-client-latest \
>                       docker-common \
>                       docker-latest \
>                       docker-latest-logrotate \
>                       docker-logrotate \
>                       docker-engine

出现如下图说明没安装过docker，不删除任何软件包

4、安装需要的软件包

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

5、设置stable镜像仓库（采用方式二）

方式一（大坑）执行命令后报错

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

报错：
1   [Errno 14] curl#35 - TCP connection reset by peer
 
2   [Errno 12] curl#35 - Timeout

方式二

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

6、更新yum软件包索引

[root@localhost ~]# yum makecache fast

7、安装DOCKER CE

[root@localhost ~]# yum -y install docker-ce

8、启动docker

[root@localhost ~]# systemctl start docker

9、测试

1）查看docker版本

[root@localhost ~]# docker version
Client:
 Version:           18.09.6
 API version:       1.39
 Go version:        go1.10.8
 Git commit:        481bc77156
 Built:             Sat May  4 02:34:58 2019
 OS/Arch:           linux/amd64
 Experimental:      false

Server: Docker Engine - Community
 Engine:
  Version:          18.09.6
  API version:      1.39 (minimum version 1.12)
  Go version:       go1.10.8
  Git commit:       481bc77
  Built:            Sat May  4 02:02:43 2019
  OS/Arch:          linux/amd64
  Experimental:     false
[root@localhost ~]# 

2）运行 hello-world

[root@localhost ~]# docker run hello-world

Hello 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.
    (amd64)
 3. The Docker daemon created a new container from that image which runs the
    executable that produces the output you are currently reading.
 4. The Docker daemon streamed that output to the Docker client, which sent it
    to your terminal.

To try something more ambitious, you can run an Ubuntu container with:
 $ docker run -it ubuntu bash

Share images, automate workflows, and more with a free Docker ID:
 https://hub.docker.com/

For more examples and ideas, visit:
 https://docs.docker.com/get-started/

[root@localhost ~]# 

11、配置镜像加速

1）、获取阿里云镜像加速器参考：https://blog.csdn.net/li1325169021/article/details/90770119

[root@localhost ~]#  mkdir -p /etc/docker
[root@localhost ~]# vim  /etc/docker/daemon.json
在文件中添加如下配置
 #阿里云镜像加速器
{"registry-mirrors": ["http://hub-mirror.c.163.com"] }
[root@localhost ~]# systemctl daemon-reload
[root@localhost ~]# systemctl restart docker

2）、配置镜像加速后重启docker可能会报错，参考：https://blog.csdn.net/li1325169021/article/details/90782846

12、卸载

[root@localhost ~]#  systemctl stop docker 
[root@localhost ~]# yum -y remove docker-ce
[root@localhost ~]# rm -rf /var/lib/docker