Ubuntu replaces the domestic apt source

Essential operations for ubuntu

1 Replace the apt mirror source

1. backup image

cp /etc/apt/sources.list /etc/apt/sources.list.bak

2. Check your ubuntu version

# 查看自己的codename
#查看自己的ubuntu版本[注意关注：DISTRIB_CODENAME，发行代号]
cat /etc/*release

# DISTRIB_CODENAME=cosmic
# 例如(下面是ubuntu的LTS长期支持版)：
# Ubuntu20.04（focal）
# Ubuntu19.10（eoan）
# Ubuntu19.04（disco）
# Ubuntu18.04（bionic）
# Ubuntu16.04（xenial）

3. Set domestic mirror source

My ubuntu version is 18.10, and there is no corresponding mirror image maintained in China, but the major versions are consistent (so I used bionic)

vim /etc/apt/sources.list

deb http://mirrors.aliyun.com/ubuntu/ bionic  main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ bionic-proposed main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic-proposed main restricted universe multiverse

4. Update the software list and complete the source change

apt update

5. Fix broken packages

apt-get install  -f

6. update software

apt-get upgrade

2 Other commands

①Firewall related

# 查看防火墙状态
sudo ufw status
# 开启/关闭防火墙
sudo ufw enable/disable