linux 配置yum源和epel软件扩展包

# 备份原yum源
sudo mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup

# 方法1：使用wget下载
sudo wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo

# 方法2：使用curl下载
sudo curl -o /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo

# 备份原EPEL源
sudo mv /etc/yum.repos.d/epel.repo /etc/yum.repos.d/epel.repo.backup 2>/dev/null
sudo mv /etc/yum.repos.d/epel-testing.repo /etc/yum.repos.d/epel-testing.repo.backup 2>/dev/null

# 下载阿里云EPEL源
sudo wget -O /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-7.repo  # CentOS 7
# 或
sudo wget -O /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-8.repo  # CentOS 8

# 清除yum缓存
sudo yum clean all

# 重建缓存
sudo yum makecache

# 验证源
sudo yum repolist