centos6.7无法安装任何软件，更换源也无法解决，发现是过期源路径变化导致。以centos6.7为例，拿走不谢
如果你的不是6.7版本，自行修改6.7为其他具体版本号。
下面为CentOS-Base.repo文件内容，其他版本的可以自行修改6.7为其他具体版本号

# 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 - Base - mirrors.aliyun.com
failovermethod=priority
baseurl=http://mirrors.aliyun.com/centos-vault/6.7/os/$basearch/
        http://mirrors.aliyun.com/centos-vault/6.7/os/$basearch/
        http://mirrors.cloud.aliyuncs.com/centos-vault/6.7/os/$basearch/
gpgcheck=1
gpgkey=http://mirrors.aliyun.com/centos-vault/6.7/RPM-GPG-KEY-CentOS-6

#released updates 
[updates]
name=CentOS-6 - Updates - mirrors.aliyun.com
failovermethod=priority
baseurl=http://mirrors.aliyun.com/centos-vault/6.7/updates/$basearch/
        http://mirrors.aliyuncs.com/centos-vault/6.7/updates/$basearch/
        http://mirrors.cloud.aliyuncs.com/centos-vault/6.7/updates/$basearch/
gpgcheck=1
gpgkey=http://mirrors.aliyun.com/centos-vault/6.7/RPM-GPG-KEY-CentOS-6

#additional packages that may be useful
[extras]
name=CentOS-6 - Extras - mirrors.aliyun.com
failovermethod=priority
baseurl=http://mirrors.aliyun.com/centos-vault/6.7/extras/$basearch/
        http://mirrors.aliyuncs.com/centos-vault/6.7/extras/$basearch/
        http://mirrors.cloud.aliyuncs.com/centos-vault/6.7/extras/$basearch/
gpgcheck=1
gpgkey=http://mirrors.aliyun.com/centos-vault/6.7/RPM-GPG-KEY-CentOS-6

#additional packages that extend functionality of existing packages
[centosplus]
name=CentOS-6 - Plus - mirrors.aliyun.com
failovermethod=priority
baseurl=http://mirrors.aliyun.com/centos-vault/6.7/centosplus/$basearch/
        http://mirrors.aliyuncs.com/centos-vault/6.7/centosplus/$basearch/
        http://mirrors.cloud.aliyuncs.com/centos-vault/6.7/centosplus/$basearch/
gpgcheck=1
enabled=0
gpgkey=http://mirrors.aliyun.com/centos-vault/6.7/RPM-GPG-KEY-CentOS-6

#contrib - packages by Centos Users
[contrib]
name=CentOS-6 - Contrib - mirrors.aliyun.com
failovermethod=priority
baseurl=http://mirrors.aliyun.com/centos-vault/6.7/contrib/$basearch/
        http://mirrors.aliyuncs.com/centos-vault/6.7/contrib/$basearch/
        http://mirrors.cloud.aliyuncs.com/centos-vault/6.7/contrib/$basearch/
gpgcheck=1
enabled=1
gpgkey=http://mirrors.aliyun.com/centos-vault/6.7/RPM-GPG-KEY-CentOS-6