yum install时，报错：Cannot find a valid baseurl for repo:base_error: cannot find a valid baseurl for repo: base

yum install时，报错：Cannot find a valid baseurl for repo:base
原因是没有配置正确的yum源。
我安装的是Centos6系统，修改使用阿里的yum源，可以使用。

这里我把我的配置文件内容贴上来，如果是使用Centos6系统可以直接覆盖用我这个，其他版本的可能需要修改下版本号就可以，具体没有试过。
yum源配置文件位置：/etc/yum.repos.d，CentOS-Base.repo即为配置文件，我把我的内容贴上来：

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-6.10 - Base - mirrors.aliyun.com
failovermethod=priority
baseurl=http://mirrors.aliyun.com/centos-vault/6.10/os/$basearch/
gpgcheck=1
gpgkey=http://mirrors.aliyun.com/centos-vault/RPM-GPG-KEY-CentOS-6

#released updates
[updates]
name=CentOS-6.10 - Updates - mirrors.aliyun.com
failovermethod=priority
baseurl=http://mirrors.aliyun.com/centos-vault/6.10/updates/$basearch/
gpgcheck=1
gpgkey=http://mirrors.aliyun.com/centos-vault/RPM-GPG-KEY-CentOS-6

#additional packages that may be useful
[extras]
name=CentOS-6.10 - Extras - mirrors.aliyun.com
failovermethod=priority
baseurl=http://mirrors.aliyun.com/centos-vault/6.10/extras/$basearch/
gpgcheck=1
gpgkey=http://mirrors.aliyun.com/centos-vault/RPM-GPG-KEY-CentOS-6

#additional packages that extend functionality of existing packages
[centosplus]
name=CentOS-6.10 - Plus - mirrors.aliyun.com
failovermethod=priority
baseurl=http://mirrors.aliyun.com/centos-vault/6.10/centosplus/$basearch/
gpgcheck=1
enabled=0
gpgkey=http://mirrors.aliyun.com/centos-vault/RPM-GPG-KEY-CentOS-6

#contrib - packages by Centos Users
[contrib]
name=CentOS-6.10 - Contrib - mirrors.aliyun.com
failovermethod=priority
baseurl=http://mirrors.aliyun.com/centos-vault/6.10/contrib/$basearch/
gpgcheck=1
enabled=0
gpgkey=http://mirrors.aliyun.com/centos-vault/RPM-GPG-KEY-CentOS-6

希望能帮到你！