修改ubuntu源为阿里源

# 更新软件源为阿里源并用它更新软件
cp /etc/apt/sources.list /etc/apt/sources.list.bak_`date "+%y_%m_%d"`
sed -i 's/http:\/\/.*.ubuntu.com/https:\/\/mirrors.aliyun.com/g' /etc/apt/sources.list
apt update
apt upgrade