安装 Docker 详见
1.确保本机上无 Docker 环境
yum remove docker \本地有 Docker 环境的话，大概会出现这种内容，没安装过的就无视这一步好了
==================================================================================================================
Package Arch Version Repository Size
==================================================================================================================
Removing:
docker x86_64 2:1.13.1-53.git774336d.el7.centos @extras 56 M
Transaction Summary
==================================================================================================================
Remove 1 Package
Installed size: 56 M
Is this ok [y/N]:
2.安装 Docker
官方似乎在推 “使用存储库进行安装” （暂时博主也不知道这是什么玩意儿）
安装存储库
yum install -y yum-utils \
device-mapper-persistent-data \
lvm2设置稳定的存储库
yum-config-manager \
--add-repo \
https://download.docker.com/linux/centos/docker-ce.repo安装当前最新 Docker-CE(社区版)
一路输入 y 就差不多了
yum install docker-ce重要的命令
// 启动 Docker
service docker start
// 停用 Docker
service docker stop
// 重启 Docker
service docker restart测试是否安装成功
docker run hello-world会自动从云仓库拉取镜像并执行，出现下列类似内容则说明 Docker 安装成功了
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/engine/userguide/