Centos 7 安装Docker-ce记录

　　以前尝试过在centos 6上安装Docker , 需要升级内核，支持aufs，比较麻烦；在使用过程中出现过Docker挂掉的情况，官方建议在64 位 centos 7 上运行，本文将安装步骤记录下来，以便查看：

　　官方提供了三种安装方式：

　　1、从 Docker Repositories 安装

　　2、RPM安装(方便，便捷)

　　3、脚本安装。

　　一、本文使用RPM的方式安装:

　　1> 下载  rpm 包 ，地址：https://download.docker.com/linux/centos/7/x86_64/stable/Packages/

　　2> 安装  yum install /path/to/package.rpm    注： /path/to/package.rpm 是rpm包下载后的路径及包名

　　　　或：以docker-ce-17.06.2.ce-1.el7.centos.x86_64.rpm 为例 ， 可以使用：

　　　　　　yum install https://download.docker.com/linux/centos/7/x86_64/stable/Packages/docker-ce-17.06.2.ce-1.el7.centos.x86_64.rpm

　　3> 启动 Docker  systemctl start docker

　　4> 检验 Docker 是否安装成功  docker run hello-world, 出现如下界面，表示Docker安装成功！

[root@localhost src]# docker run hello-world
Unable to find image 'hello-world:latest' locally
latest: Pulling from library/hello-world
b04784fba78d: Pull complete
Digest: sha256:f3b3b28a45160805bb16542c9531888519430e9e6d6ffc09d72261b0d26ff74f
Status: Downloaded newer image for hello-world:latest
 
Hello from Docker!
This message shows that your installation appears to be working correctly.
 
To generate this message, Docker took the following steps:
 . The Docker client contacted the Docker daemon.
 . The Docker daemon pulled the "hello-world" image from the Docker Hub.
 . The Docker daemon created a new container from that image which runs the
    executable that produces the output you are currently reading.
 . 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://cloud.docker.com/
 
For more examples and ideas, visit:
 https://docs.docker.com/engine/userguide/

　　二、卸载 Docker 的步骤：
　　1、卸载 docker 相关的包  yum remove docker-ce

　　2、删除 docker 相关文件  rm -rf /var/lib/docker