linuxexpert-practice-labs/labs/lpic-1/107-1-users-and-groups/README.md

LPIC-1 107.1: User and group accounts

Creating users and groups, supplementary groups, password ageing, system accounts, and what deleting a user leaves behind.

Before you start

The lab creates group testers and users pat, ken and lou. Their password is Lab-Pass-1. ken owns a file outside his home directory.

Tasks

1. Create group developers, and user dana with a home directory, the comment Dana Lee, the shell /bin/sh and the supplementary group developers. Read the new lines in /etc/passwd, /etc/shadow and /etc/group, and the new home directory.
2. Add dana to a second group, testers, with usermod -aG. Then run usermod -G developers dana, and write the name of the group she lost to /root/lab-answers/2.
3. Make dana's password expire every 30 days, with a 7-day warning. Check with chage -l and the fields in /etc/shadow.
4. Force pat to change her password with chage -d 0, then log in as pat (on the console, or with ssh pat@localhost) and see what happens.
5. Create a system account appsvc with a nologin shell, and try su - appsvc.
6. Delete user ken with userdel -r and user lou without it. Then find the files they left behind with find / -xdev -nouser, and write those paths to /root/lab-answers/6, one per line.

Hints

• groupadd, useradd -m -c -s -G, getent passwd dana, ls -la.
• id dana before and after; -a is what keeps the other groups.
• chage -M -W, chage -l dana; fields 5 and 6 of /etc/shadow.
• chage -l pat shows "password must be changed".
• useradd -r -s (the path of nologin is in /etc/shells, or try command -v nologin).
• userdel with and without -r; find / -xdev -nouser 2>/dev/null.