問題1：Confirm Hosts時，遇到Repository的問題

Error Summary
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Repository base is listed more than once in the configuration
Repository updates is listed more than once in the configuration
Repository extras is listed more than once in the configuration
Repository centosplus is listed more than once in the configuration

出現類似這種錯誤的，是yum源的問題，簡單來說是你配置的yum倉庫出現重複，需要僅僅留一個就可以了。具體做法就是：將/etc/repos.d/*.repo僅僅留下

再重來，就不報上面的錯誤了。

問題2:Confirm Hosts時，遇到 Transaction Check Error 的問題

Transaction check error: file /etc/sudoers.d from install of ambari-agent-2.0.0-151.x86_64 conflicts with file from package sudo-1.8.6p7-13.el7.x86_64