RH124-05 管理本地用户和组-2

Posted 2020-09-19

管理本地账号

5.3 c

相关命令： useradd ,usermod ,userdel,passwd , groupadd ,groupmod,gpasswd,groupdel

相关文件： /etc/login.defs  , /etc/passwd , /etc/shadow , /etc/gpasswd , /etc/gshadow

需要掌握： 创建，修改，删除用户、用户组，修改用户组身份，设定用户密码

添加用户前需要确定:

确定用户的默认组是否有特殊要求

确定用户是否允许登陆

确定用户的密码策略

确定用户的有效期

确定用户的uid是否有特殊要求

useradd，usermod 的参数：

-u  指定用户的uid

-c  添加用户注释

-g  指定用用户的默认组

-G  指定用户的附加组

-a  追加更多的附加组，必须和-G使用: -aG

-d  指定用户的家目录

-m  家目录迁移，必须和-d一起使用

-s  指定用户默认shell

-L  锁定用户

-U  解锁用户

groupadd命令的需要掌握的参数:

-g

groupmod命令的需要掌握的参数:

-g

-n

练习： 考试必考知识点

建立用户juliet, romeo,  hamlet，reba, dolly, and elvis

建立用户组，组ID要求为30000，组名为shakespeare

建立用户组，组名为artists

要求把shakespeare作为用户juliet, romeo和 hamlet的附加组

要求把artists作为用户reba, dolly 和 elvis的附加组

要求artists同时作为用户romeo的另外一个附加组(之前的附加组还继续使用)

5.4 管理用户密码

相关文件： /etc/passwd,/etc/shadow

相关命令： chage,usermod

chage命令的参数:

-l 显示帐户年龄信息

-E   # chage -E 2014-12-28 romeo

-d   # -d 0 下次登陆系统强制修改密码

-M 将两次改变密码之间相距的最大天数设为“最大天数”

-m   将两次改变密码之间相距的最小天数设为“最小天数”

-W 将过期警告天数设为“警告天数”

-I 过期 INACTIVE 天数后，设定密码为失效状态

练习： 在server虚拟机上完成。  当romeo用户第一次登陆系统的时候(默认登陆密码为romeo)，必须要求强制更改密码。密码有效期为90天，账号将在180天后过期

实验： 重置server虚拟机，然后在上面完成操作

新建用户sspade, bboop, and dtracy，密码有效期为30天，默认密码都为redhat

新建用户组consultants，组ID必须为40000，并且该组作为上面三个用户的附加组

把上述三个用户的账号有效期设定为90天后

bboop用户的密码有效期更改为15天

所有用户在第一登陆的时候都必须强制修改密码

实验完毕，提交# lab localusers grade 

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第五章目录

useradd tom

[[email protected] ~]# grep tom /etc/passwd   在某个目录中的文件 找某个关键字，如果有则输出

tom:x:1001:1001::/home/tom:/bin/bash

[[email protected] ~]# id tom 

uid=1001(tom) gid=1001(tom) groups=1001(tom)

[[email protected] ~]# grep tom /etc/group          如果没有指定组，则会默认加一个与它相同的组，并且会一个家目录。

tom:x:1001:

[[email protected] ~]# cd /home

[[email protected] home]# ls

student  tom

[[email protected] home]# passwd tom           给用户加一个密码

Changing password for user tom.

New password: 

BAD PASSWORD: The password is shorter than 8 characters

Retype new password: 

[[email protected] home]# ssh [email protected]

The authenticity of host ‘localhost (::1)‘ can‘t be established.

ECDSA key fingerprint is eb:24:0e:07:96:26:b1:04:c2:37:0c:78:2d:bc:b0:08.

Are you sure you want to continue connecting (yes/no)? yes

创建mary

[[email protected] home]# useradd -u 1500 -d /home/imary -s /sbin/nologin mary

[[email protected] home]# id mary

uid=1500(mary) gid=1500(mary) groups=1500(mary)

[[email protected] home]# grep mary /etc/gropu

grep: /etc/gropu: No such file or directory

[[email protected] home]# grep mary /etc/group

mary:x:1500:

修改mary的组和bash等信息

[[email protected] home]# usermod -c "i am mary ,i am a pretty girl" -G tom -s /bin/bash mary

[[email protected] home]# id mary

uid=1500(mary) gid=1500(mary) groups=1500(mary),1001(tom)

[[email protected] home]# grep mary /etc/passwd

mary:x:1500:1500:i am mary ,i am a pretty girl:/home/imary:/bin/bash

[[email protected] home]# 

[[email protected] home]# usermod -aG daemon mary   再加一个组

[[email protected] home]# id mary

uid=1500(mary) gid=1500(mary) groups=1500(mary),2(daemon),1001(tom)

[[email protected] home]# 

[[email protected] home]# usermod -L mary 锁定

[[email protected] home]# grep mary /etc/shadow

mary:!!:17306:0:99999:7:::

[[email protected] home]# ^C

[[email protected] home]# usermod -U mary   解锁

[[email protected] home]# grep mary /etc/shadow

mary:!:17306:0:99999:7:::

[[email protected] home]# 

删除，不加-r会留下邮件和家目录

[[email protected] home]# userdel mary

[[email protected] home]# ls -ld /home/imary

drwx------. 4 1500 1500 88 May 20 14:13 /home/imary

[[email protected] home]# ls -l /var/mail

lrwxrwxrwx. 1 root root 10 May  7  2014 /var/mail -> spool/mail

[[email protected] home]# ls -l /var/mail/

total 0

-rw-rw----. 1    1500 mail 0 May 20 14:13 mary

-rw-rw----. 1 rpc     mail 0 May  7  2014 rpc

-rw-rw----. 1 student mail 0 Jul 11  2014 student

-rw-rw----. 1 tom     mail 0 May 20 13:57 tom

[[email protected] home]# userdel -r tom

[[email protected] home]# ls -l /var/mail

lrwxrwxrwx. 1 root root 10 May  7  2014 /var/mail -> spool/mail

[[email protected] home]# ls -l /var/mail/

total 0

-rw-rw----. 1    1500 mail 0 May 20 14:13 mary

-rw-rw----. 1 rpc     mail 0 May  7  2014 rpc

-rw-rw----. 1 student mail 0 Jul 11  2014 student

[[email protected] home]# grep admin /etc/group

admin:x:1001:

[[email protected] home]# groupadd -g 1500 dba

[[email protected] home]# grep dba /etc/group

dba:x:1500:

[[email protected] home]# groupmod -g 2500 dba   改id

[[email protected] home]# grep dba /etc/group

dba:x:2500:

[[email protected] home]# groupmod -n dbadmin dba  改名字

[[email protected] home]# grep dba /etc/group

dbadmin:x:2500:

[[email protected] home]# 

组加密码，并用student组临时改成admin，只是在这次的会话中登陆 ，重新登陆就没有了

[[email protected] home]# gpasswd admin

Changing the password for group admin

New Password: 

Re-enter new password: 

[[email protected] home]# grep admin /etc/gshadow

admin:$6$YCWYZDTZINF0tT$x.LHtjRsrVhLRQmdvyM3iCLLJkqp3DJqxlfPAoF.ozfegXjXC9kSK3k8cd7ckmstW7MHNJrpH9R7zaCv8xZiR.::

dbadmin:!::

[[email protected] home]# grep admin /etc/passwd

[[email protected] home]# ext

bash: ext: command not found...

[[email protected] home]# exit

logout

[[email protected] Desktop]$ newgrp admin

Password: 

[[email protected] Desktop]$ id

uid=1000(student) gid=1001(admin) groups=1000(student),10(wheel),1001(admin) context=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023

[[email protected] Desktop]$ 

练习：

[[email protected] Desktop]# useradd juliet

[[email protected] Desktop]# useradd romeo

[[email protected] Desktop]# useradd hamlet

[[email protected] Desktop]# useradd dolly

[[email protected] Desktop]# useraddd elvis

bash: useraddd: command not found...

Similar command is: ‘useradd‘

[[email protected] Desktop]# useradd elvis

[[email protected] Desktop]# useradd reba

[[email protected] Desktop]# gropadd -g 3000 shakespeare

bash: gropadd: command not found...

[[email protected] Desktop]# groupadd -g 3000 shakespeare

[[email protected] Desktop]# tail -6 /etc/group

romeo:x:1002:

hamlet:x:1003:

dolly:x:1004:

elvis:x:1005:

reba:x:1006:

shakespeare:x:3000:

[[email protected] Desktop]# tail -7 /etc/group

juliet:x:2501:

romeo:x:1002:

hamlet:x:1003:

dolly:x:1004:

elvis:x:1005:

reba:x:1006:

shakespeare:x:3000:

[[email protected] Desktop]# tail -2 /etc/group

reba:x:1006:

shakespeare:x:3000:

加组两种访求 

[[email protected] Desktop]# id juliet

uid=1001(juliet) gid=2501(juliet) groups=2501(juliet)

[[email protected] Desktop]# usermod -Gshakespeare juliet

[[email protected] Desktop]# id juliet

uid=1001(juliet) gid=2501(juliet) groups=2501(juliet),3000(shakespeare)

[[email protected] Desktop]# gpasswd -a romeo shakespeare

再加一个附加组   usrmod -aG artists romeo

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