初始化配置Ubuntu 20.04

目标：安装好一台ubuntu server以后，就行初始化配置，包括：1，网络配置；2，更换国内软件源；3，设置hostname

前提：最小化安装一台Ubuntu 20.04的server

1.网络配置

进入命令行
sudo vim /etc/netplan/00-installer-config.yaml

network:
  ethernets:
    ens33:
      dhcp4: false
      addresses:
        - 192.168.216.30/24
      routes:
        - to: default
          via: 192.168.216.2
      nameservers:
        addresses:
          - 192.168.216.2
          - 114.114.114.114
          - 8.8.8.8
  version: 2

sudo netplan apply
ip addr

2.更换国内阿里软件源

sudo mv /etc/apt/sources.list /etc/apt/sources.list.bak
sudo vim /etc/apt/sources.list

deb http://mirrors.aliyun.com/ubuntu/ focal main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ focal main restricted universe multiverse

deb http://mirrors.aliyun.com/ubuntu/ focal-security main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ focal-security main restricted universe multiverse

deb http://mirrors.aliyun.com/ubuntu/ focal-updates main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ focal-updates main restricted universe multiverse

deb http://mirrors.aliyun.com/ubuntu/ focal-proposed main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ focal-proposed main restricted universe multiverse

deb http://mirrors.aliyun.com/ubuntu/ focal-backports main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ focal-backports main restricted universe multiverse

sudo apt-get update

3.设置主机名

sudo hostnamectl set-hostname my-ubuntu
sudo reboot

4.其他设置

4.1设置允许root用户ssh登陆（测试环境）

sudo apt install ssh
sudo vim /etc/ssh/sshd_config
添加
PermitRootLogin yes
sudo systemctl restart ssh