• 添加root用户
• 添加新用户并赋予权限

文件只读，无法更改

root@ubuntu-server:/home/ubuntu# vi /etc/sudoers
root@ubuntu-server:/home/ubuntu# vi /etc/sudoers
root@ubuntu-server:/home/ubuntu# chmod -R 777  /etc/sudoers
root@ubuntu-server:/home/ubuntu# vi /etc/sudoers
root@ubuntu-server:/home/ubuntu# chmod 0440 /etc/sudoers
root@ubuntu-server:/home/ubuntu# chmod -R 777  /etc/sudoers
root@ubuntu-server:/home/ubuntu# vi /etc/sudoers
root@ubuntu-server:/home/ubuntu# chmod 0440 /etc/sudoers
root@ubuntu-server:/home/ubuntu#

证明自己已经在root用户组

zhangbin@ubuntu-server:~$ sudo -i
[sudo] password for zhangbin:
root@ubuntu-server:~#