在yum 时出现错误：

Errors during downloading metadata for repository 'root_1212124324234':
  - Curl error (37): Couldn't read a file:// file for file:///root/1212124324234/repodata/repomd.xml [Couldn't open file /root/1212124324234/repodata/repomd.xml]
错误：为仓库 'root_1212124324234' 下载元数据失败 : Cannot download repomd.xml: Cannot download repodata/repomd.xml: All mirrors were tried
 

解决问题：

1.在/etc/yum.repos.d文件夹下存在root_1212124324234.repo文件

2.删除root_1212124324234.repo文件

3.重新添加yum源

cat <<EOF > /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=http://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64
enabled=1
gpgcheck=0
repo_gpgcheck=0
gpgkey=http://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg
        http://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
EOF

4.重新执行：

yum clean all && yum makecache

成功后，可以yum你需要文件即可！！！