Centos 7 yum不了 提示One of the configured repositories failed 报错

yum upadate显示报错

One of the configured repositories failed (centos),
and yum doesn't have enough cached data to continue. At this point the only
safe thing yum can do is fail. There are a few ways to work "fix" this:

 1. Contact the upstream for the repository and get them to fix the problem.

 2. Reconfigure the baseurl/etc. for the repository, to point to a working
    upstream. This is most often useful if you are using a newer
    distribution release than is supported by the repository (and the
    packages for the previous distribution release still work).

 3. Run the command with the repository temporarily disabled
        yum --disablerepo=centos ...

 4. Disable the repository permanently, so yum won't use it by default. Yum
    will then just ignore the repository until you permanently enable it
    again or use --enablerepo for temporary usage:

        yum-config-manager --disable centos
    or
        subscription-manager repos --disable=centos

 5. Configure the failing repository to be skipped, if it is unavailable.
    Note that yum will try to contact the repo. when it runs most commands,
    so will have to try and fail each time (and thus. yum will be be much
    slower). If it is a very temporary problem though, this is often a nice
    compromise:

        yum-config-manager --save --setopt=centos.skip_if_unavailable=true

如何解决

你这个问题之前可以正常运行吗

YUM源的问题，然后看报错，你弄了本地源？
解决很简单啊，明确你的yum源文件是否配置正确，
如果不知道，就备份现在的，然后删除，之后重新配置就OK了。

我喜欢用阿里源，设置方法，如下：
阿里源基础包设置方法：https://developer.aliyun.com/mirror/centos
阿里云EPEL源设置方法：https://developer.aliyun.com/mirror/epel
如果是本地源，要明确创建是否正确。