Kylin3.3 添加CentOS 7的源

创建CentOS-Base.repo文件
vi /etc/yum.repos.d/CentOS-Base.repo
内容为：

# 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-7 - Base
#mirrorlist=http://mirrorlist.centos.org/?release=7&arch=$basearch&repo=os&infra=$infra
baseurl=http://mirror.centos.org/centos/7/os/$basearch/
gpgcheck=0
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7
#released updates 

[updates]
name=CentOS-7 - Updates
#mirrorlist=http://mirrorlist.centos.org/?release=7&arch=$basearch&repo=updates&infra=$infra
baseurl=http://mirror.centos.org/centos/7/updates/$basearch/
gpgcheck=0
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7 

#additional packages that may be useful
[extras]
name=CentOS-7 - Extras
#mirrorlist=http://mirrorlist.centos.org/?release=7&arch=$basearch&repo=extras&infra=$infra
baseurl=http://mirror.centos.org/centos/7/extras/$basearch/
gpgcheck=0
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7 

#additional packages that extend functionality of existing packages
[centosplus]
name=CentOS-7 - Plus
#mirrorlist=http://mirrorlist.centos.org/?release=7&arch=$basearch&repo=centosplus&infra=$infra
baseurl=http://mirror.centos.org/centos/7/centosplus/$basearch/
gpgcheck=0
enabled=0
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7

运行命令，看是否有错误提示
yum repolist