20210907：

镜像使用：

ubuntu-21.04-desktop-amd64.iso

默认root用户未开启、不登录

sudo su

sudo passwd root

apt-get install vim

sudo vim /usr/share/lightdm/lightdm.conf.d/50-ubuntu.conf

增加：

greeter-show-manual-login=true #手工输入登陆系统的用户名和密码
allow-guest=false #不允许guest登录（可选）

reboot

apt-get install openssh-server

apt-get upgrade

防火墙：
ufw disable          //关闭防火墙
ufw status
ufw enable    //开启防火墙
ufw default deny        //拒接所有外来访问，本机能正常访问外部
ufw allow 80  //开放21端口
ufw reload  //重启
ufw delete allow 22 //删除普通端口
ufw allow 8001/tcp  //指定开放8001的tcp协议
ufw delete allow 8001/tcp
ufw allow from 192.168.121.1 // 指定ip为192.168.121.1的计算机操作所有端口
ufw delete allow from 192.168.121.1
ufw allow from 192.168.121.2 to any port 3306 // 开放指定ip为192.168.121.2的计算机访问本机的3306端口
ufw delete allow from 192.168.121.2 to any port 3306

nginx：
apt install nginx fcgiwrap nginx-doc
nginx -v
vim /etc/nginx/nginx.conf
service nginx start
service nginx status

apache2（httpd）:
apt install apache2
service apache2 status
service apache2 start
vim /etc/apache2/apache2.conf

PHP:
apt install php
apt install php-fpm
service php-fpm status //安装时要注意看版本号
service php-fpm start

MySQL:
apt install mysql-server
service mysql status
mysql_secure_installation
mysql -uroot -p
select host,user,authentication_string,plugin from user;
update user set host='%' where user='root';
alter user 'root'@'%' identified by '123456' password expire never;
alter user 'root'@'%' identified with mysql_native_password by '123456';
flush privileges;