centos：添加用户

初步进入centos学习，配置用户

1，创建用户

创建用户 hadoop

[root@master spark]# useradd hadoop
[root@master spark]#

2，创建密码

[root@master spark]# passwd hadoop
Changing password for user hadoop.
New password: 
BAD PASSWORD: The password is shorter than 8 characters
Retype new password: 
passwd: all authentication tokens updated successfully.

3，用户授权

创建账户必须授权，不然，个人用户的权限只可以在本home下有权限，其他的必须有授权，一般需要root的权限
sudo的命令授权一般在sudoers里面
找到sudoer文件位置
看下文件的权限

[spark@master ~]$ sudoers
-bash: sudoers: command not found
[spark@master ~]$ whereis sudoers
sudoers: /etc/sudoers /etc/sudoers.d /usr/share/man/man5/sudoers.5.gz

只读的文件，可以修改权限或者强行保存

[root@centos etc]# vi /etc/sudoers
## Allow root to run any commands anywher
root   ALL=(ALL) ALL #这个是新增的用户 
hadoop ALL=(ALL) ALL  #这个是新增的用户

用x！命令强制保存

或者修改文件权限

chmod -v u+w /etc/sudoers

配置完了，最好把权限收回

chmod -v u-w /etc/sudoers

到这里基本结束了。

可以用新用户登陆了，使用sudo命令这块

[hadoop@centos ~]$ sudo cat /etc/passwd
We trust you have received the usual lecture from the local System
Administrator. It usually boils down to these three things:
#1) Respect the privacy of others.
#2) Think before you type.
#3) With great power comes great responsibility.

[sudo] password for hadoop: