错误信息
使用 yum-config-manager命令时错误信息如下
sudo yum-config-manager \
> --add-repo \
> https://download.docker.com/linux/centos/docker-ce.repo
sudo: yum-config-manager: command not found
解决办法
第一步：
|---------------------------------------|
| sudo yum -y install yum-utils |
如果提示安装成功，则可用执行上述指令，如果提示如下错误，则执行下一步
|--------------------------------------------------------------------------------------------------------------------------------|
| Package yum-3.4.3-168.el7.centos.noarch already installed and latest version No package utils available. Nothing to do |
第二步：删除 yum-3.4.3-168.el7.centos.noarch
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| [planck@NZTCN001 ~]$ sudo yum remove yum-3.4.3-168.el7.centos.noarch Loaded plugins: fastestmirror Resolving Dependencies --> Running transaction check ---> Package yum.noarch 0:3.4.3-168.el7.centos will be erased --> Processing Dependency: yum for package: policycoreutils-devel-2.5-34.el7.x86_64 --> Processing Dependency: yum >= 3.0 for package: yum-plugin-fastestmirror-1.1.31-54.el7_8.noarch --> Processing Dependency: yum >= 3.4.3-143 for package: yum-utils-1.1.31-54.el7_8.noarch --> Running transaction check ---> Package policycoreutils-devel.x86_64 0:2.5-34.el7 will be erased ---> Package yum-plugin-fastestmirror.noarch 0:1.1.31-54.el7_8 will be erased ---> Package yum-utils.noarch 0:1.1.31-54.el7_8 will be erased --> Finished Dependency Resolution Error: Trying to remove "yum", which is protected |
第三步：更换阿里镜像源，重新安装 yum-utils (经过测试，centos 7.9 自带的镜像源安装yum-utils，yum-config-manager 不可用，不知道是系统都是这个问题还是拷贝的系统问题，有待验证)
更换阿里镜像源请参考：yum源-镜像源
再重新安装yum-utils
sudo yum -y install yum-utils