慕课网神思者老师课常资料带的布署工具中，自带的liunx 系统centos7 yum发现不能安装软件，比如docker 解决方案
首先我们安装好虚拟机启动系统centos7 尝试安装任何软件都会报仓库错误
第一反应就是更新yum yum update 由于仓库不对更新肯定不行了
第二反是 更新仓库
使用 mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup
wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo
但是发现wget最小化版没有安装，还是得解决仓库问题
查看仓库 yum pepolist all 会看到好多仓库，可能还有些禁用了
要想启用某个仓库只需在某个仓库的配置文件将enabled = 0 改为1 就好，但是肯定问题 不在这儿，这些配置老师不会运个东西，
想了一下如果是仓库源有问题 ，我们就将一下正常的仓库内容复制过来，所以我在我们的云主机的文件中复制一个配置过来。
修改这个仓库
vi CentOS-Base.repo
# CentOS-Base.repo # # The mirror system uses the connecting IP address of the client and the # update status of each mirror to pick mirrors that are updated to and # geographically close to the client. You should use this for CentOS updates # unless you are manually picking other mirrors. # # If the mirrorlist= does not work for you, as a fall back you can try the # remarked out baseurl= line instead. # #[base] name=CentOS-$releasever - Base - mirrors.aliyun.com failovermethod=priority baseurl=http://mirrors.aliyun.com/centos/$releasever/os/$basearch/http://mirrors.aliyuncs.com/centos/$releasever/os/$basearch/http://mirrors.cloud.aliyuncs.com/centos/$releasever/os/$basearch/ gpgcheck=1 gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7 #released updates [updates] name=CentOS-$releasever - Updates - mirrors.aliyun.com failovermethod=priority baseurl=http://mirrors.aliyun.com/centos/$releasever/updates/$basearch/http://mirrors.aliyuncs.com/centos/$releasever/updates/$basearch/http://mirrors.cloud.aliyuncs.com/centos/$releasever/updates/$basearch/ gpgcheck=1 gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7 #additional packages that may be useful [extras] name=CentOS-$releasever - Extras - mirrors.aliyun.com failovermethod=priority baseurl=http://mirrors.aliyun.com/centos/$releasever/extras/$basearch/http://mirrors.aliyuncs.com/centos/$releasever/extras/$basearch/http://mirrors.cloud.aliyuncs.com/centos/$releasever/extras/$basearch/ gpgcheck=1 gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7 #additional packages that extend functionality of existing packages [centosplus] name=CentOS-$releasever - Plus - mirrors.aliyun.com failovermethod=priority baseurl=http://mirrors.aliyun.com/centos/$releasever/centosplus/$basearch/http://mirrors.aliyuncs.com/centos/$releasever/centosplus/$basearch/http://mirrors.cloud.aliyuncs.com/centos/$releasever/centosplus/$basearch/ gpgcheck=1 enabled=0 gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7 #contrib - packages by Centos Users [contrib] name=CentOS-$releasever - Contrib - mirrors.aliyun.com failovermethod=priority baseurl=http://mirrors.aliyun.com/centos/$releasever/contrib/$basearch/http://mirrors.aliyuncs.com/centos/$releasever/contrib/$basearch/http://mirrors.cloud.aliyuncs.com/centos/$releasever/contrib/$basearch/ gpgcheck=1 enabled=0 gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7
我是将里面全删 了，然后粘上这个正确的，然后yum 正常可以更新了。问题解决
总结一下，配置仓库有问题 我们就拿 一个正确的仓库文件替换一下，因为这个上最小化安装的才有这么多麻烦，如果我们是正确安装有带基础的网络服务的安装，系统就没有这么麻烦
