Centos7 yum usage errors caused a number of problems
I had an error using the yum command in the Centos virtual machine
The question bothered me for several days
I gave it a try
The default warehouse on the special network in China is not available
I have configured alibaba's warehouse address
But it didn't work
I also changed the mirror source of a university in China
It still doesn't work
I know this is not the only part of the problem
I think it is very likely that there is a problem with THE DNS service through querying relevant information
I tried the most famous Google DNS 8.8.8.8
And the network provider I used provided the address 114.114.114.114
Find the problem is still unresolved
One of the virtual machines even had an error restarting the network
（systemctl restart network）
It's confusing to find problems recursively
I came across a blog entry
He said because the centos7 Mini was installed
Almost none of the tools are pre-installed
The Named server does not exist at all
The solutions given
Yum install bind
The chkconfig named on
But yum is just not available
I went through the k8s tutorial again
Found out I missed an operation
This is the tool that is pre-installed when centos is installed
I tried to reinstall my three nodes
It will take some time, I'm afraid
But it would be all right if we could solve this problem
Sure enough, the tutorial doesn't look too hard, but there are all kinds of problems with real hands-on work