centos7.5安装docker

1.更新yum　　

yum update

2.安装需要的软件包， yum-util 提供yum-config-manager功能，另外两个是devicemapper驱动依赖的

yum install -y yum-utils device-mapper-persistent-data lvm2

3.设置yum源

yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo

4.安装Docker

docker-ce-17.12.1.ce是作者选择的版本。

yum install docker-ce-17.12.1.ce

5.启动Docker，命令：systemctl start docker，然后加入开机启动，如下

systemctl start docker
systemctl enable docker

6.验证安装是否成功

docker version

安装成功如下

Client:
 Version:    17.12.1-ce
 API version:    1.35
 Go version:    go1.9.4
 Git commit:    7390fc6
 Built:    Tue Feb 27 22:15:20 2018
 OS/Arch:    linux/amd64

Server:
 Engine:
  Version:    17.12.1-ce
  API version:    1.35 (minimum version 1.12)
  Go version:    go1.9.4
  Git commit:    7390fc6
  Built:    Tue Feb 27 22:17:54 2018
  OS/Arch:    linux/amd64
  Experimental:    false