apt源
Ubuntu采用apt作为软件安装工具，其镜像源列表记录在/etc/apt/source.list文件中。
首先将source.list复制为source.list.bak备份。
cp /etc/apt/sources.list /etc/apt/sources.list.back
修改完成后保存source.list文件，需要执行命令后才能生效：
sudo apt update -y
本文为 Ubuntu 22.04 的阿里云镜像源列表。若为其他版本，将所有jammy更改为其他版本代号即可。 常用的Ubuntu版本代号如下： Ubuntu 22.04：jammy Ubuntu 20.04：focal Ubuntu 18.04：bionic Ubuntu 16.04：xenia
vim /etc/apt/source.list
将文件内容清空，然后复制下方代码粘贴，wq保存退出即可。
deb https://mirrors.aliyun.com/ubuntu/ jammy main restricted universe multiverse
deb-src https://mirrors.aliyun.com/ubuntu/ jammy main restricted universe multiverse
deb https://mirrors.aliyun.com/ubuntu/ jammy-security main restricted universe multiverse
deb-src https://mirrors.aliyun.com/ubuntu/ jammy-security main restricted universe multiverse
deb https://mirrors.aliyun.com/ubuntu/ jammy-updates main restricted universe multiverse
deb-src https://mirrors.aliyun.com/ubuntu/ jammy-updates main restricted universe multiverse
# deb https://mirrors.aliyun.com/ubuntu/ jammy-proposed main restricted universe multiverse
# deb-src https://mirrors.aliyun.com/ubuntu/ jammy-proposed main restricted universe multiverse
deb https://mirrors.aliyun.com/ubuntu/ jammy-backports main restricted universe multiverse
deb-src https://mirrors.aliyun.com/ubuntu/ jammy-backports main restricted universe multiverse