使用阿里镜像 https://mirrors.aliyun.com

sed -i 's/dl-cdn.alpinelinux.org/mirrors.aliyun.com/g' /etc/apk/repositories

使用科大镜像 http://mirrors.ustc.edu.cn

sed -i 's/dl-cdn.alpinelinux.org/mirrors.ustc.edu.cn/g' /etc/apk/repositories