最近买了个服务器，阿里云的，想安装一下docker为了springcloud部署做铺垫。

yum install -y yum-utils
[root@shursulei ~]# yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo
[root@shursulei ~]# yum makecache fast

上面首先安装了yum-utils，它提供了yum-config-manager管理工具，然后安装了最新稳定版本的Repository文件，最后更新yum的package索引。

Docker版本    命令
Docker CE   sudo yum install docker-ce
Docker EE   sudo yum install docker-ee
安装ce版本
[root@shursulei ~]# yum install docker-ce

启动Docker了，执行如下命令，启动Docker（Docker Engine）：
systemctl start docker
　可以查看一下当前系统上的进程，执行ps -ef | grep docker确认Docker已经启动：

测试运行：

[root@shursulei ~]# docker run hello-world
Unable to find image 'hello-world:latest' locally
latest: Pulling from library/hello-world
ca4f61b1923c: Pull complete 
Digest: sha256:66ef312bbac49c39a89aa9bcc3cb4f3c9e7de3788c944158df3ee0176d32b751
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:
 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://cloud.docker.com/

For more examples and ideas, visit:
 https://docs.docker.com/engine/userguide/

docker run hello-world