CentOS 6 yum安装软件报错 YumRepo Error

在CentOS 6的机器上使用yum 安装软件报错：

[root@665daec6fea1 ~]# yum install apr
Loaded plugins: fastestmirror, ovl
Setting up Install Process
Loading mirror speeds from cached hostfile
YumRepo Error: All mirror URLs are not using ftp, http[s] or file.
 Eg. Invalid release/repo/arch combination/
removing mirrorlist with no valid mirrors: /var/cache/yum/x86_64/6/base/mirrorlist.txt
Error: Cannot find a valid baseurl for repo: base

使用yum update命令也是一样：

[root@665daec6fea1 ~]# yum update
Loaded plugins: fastestmirror, ovl
Setting up Update Process
Loading mirror speeds from cached hostfile
YumRepo Error: All mirror URLs are not using ftp, http[s] or file.
 Eg. Invalid release/repo/arch combination/
removing mirrorlist with no valid mirrors: /var/cache/yum/x86_64/6/base/mirrorlist.txt
Error: Cannot find a valid baseurl for repo: base

看错误提示，似乎是说找不到有效的baseurl。所以要解决这个问题，还要从baseurl着手。
从官方邮件可知，CentOS 6自从2020年11月30日开始，官方不再维护，所以连带着原来的yum存储库也不能用了。

但是邮件里说得很明白，它给出了迁移后的存储库的链接地址，这时候我们只需要更新yum存储库的镜像列表，就可以正常使用了。
步骤如下：
进入到/etc/yum.repos.d目录下：

cd /etc/yum.repos.d

备份原来的CentOS-Base.repo文件：

cp CentOS-Base.repo CentOS-Base.repo.old

修改CentOS-Base.repo文件：

vi CentOS-Base.repo

主要修改内容如下：

[base]
name=CentOS-$releasever - Base
# mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=os&infra=$infra
# baseurl=http://mirror.centos.org/centos/$releasever/os/$basearch/
baseurl=https://vault.centos.org/6.10/os/$basearch/
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-6

# released updates
[updates]
name=CentOS-$releasever - Updates
# mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=updates&infra=$infra
# baseurl=http://mirror.centos.org/centos/$releasever/updates/$basearch/
baseurl=https://vault.centos.org/6.10/updates/$basearch/
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-6

# additional packages that may be useful
[extras]
name=CentOS-$releasever - Extras
# mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=extras&infra=$infra
# baseurl=http://mirror.centos.org/centos/$releasever/extras/$basearch/
baseurl=https://vault.centos.org/6.10/extras/$basearch/
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-6

清理yum 缓存

yum clean all

执行 yum update

yum update

再次安装成功：

[root@665daec6fea1 ~]# yum install apr
Loaded plugins: fastestmirror, ovl
Setting up Install Process
Loading mirror speeds from cached hostfile
YumRepo Error: All mirror URLs are not using ftp, http[s] or file.
 Eg. Invalid release/repo/arch combination/
YumRepo Error: All mirror URLs are not using ftp, http[s] or file.
 Eg. Invalid release/repo/arch combination/
YumRepo Error: All mirror URLs are not using ftp, http[s] or file.
 Eg. Invalid release/repo/arch combination/
Resolving Dependencies
--> Running transaction check
---> Package apr.x86_64 0:1.3.9-5.el6_9.1 will be installed
--> Finished Dependency Resolution

Dependencies Resolved

================================================================================================================
 Package               Arch                     Version                            Repository              Size
================================================================================================================
Installing:
 apr                   x86_64                   1.3.9-5.el6_9.1                    base                   124 k

Transaction Summary
================================================================================================================
Install       1 Package(s)

Total download size: 124 k
Installed size: 296 k
Is this ok [y/N]: y
Downloading Packages:
apr-1.3.9-5.el6_9.1.x86_64.rpm                                                           | 124 kB     00:00     
Running rpm_check_debug
Running Transaction Test
Transaction Test Succeeded
Running Transaction
  Installing : apr-1.3.9-5.el6_9.1.x86_64                                                                   1/1 
/sbin/ldconfig: /usr/lib/libcriterion.so.3 is not a symbolic link

/sbin/ldconfig: /usr/lib64/libcriterion.so.3 is not a symbolic link

  Verifying  : apr-1.3.9-5.el6_9.1.x86_64                                                                   1/1 

Installed:
  apr.x86_64 0:1.3.9-5.el6_9.1                                                                                  

Complete!

至此，大功告成。