Creating and managing local user accounts

Do these on your own system. They get harder. Check each result, then tick it off.

1. Warm-upDone

   Decode one account line

   Print the /etc/passwd line for alex and name each of its seven fields. Then show the same account through getent, and say why that is the better habit.

   Check your result

   The line looks like alex:x:1000:1000:alex:/home/alex:/bin/bash: name, password placeholder x, UID, primary GID, comment, home, shell. getent passwd alex prints the same line and also finds users from LDAP or IdM.

   Hint

   grep '^alex:' /etc/passwd and getent passwd alex.

   Solution

   grep '^alex:' /etc/passwd
   getent passwd alex

2. PracticeDone

   Create a normal user

   Create the user lena with UID 1500, comment Lena Berg, and the default home and shell. Set her password to Redhat123! without a prompt. Show her id and confirm her home directory exists and holds the files from /etc/skel.

   Check your result

   id lena shows uid=1500(lena) gid=1500(lena). ls -A /home/lena shows .bash_logout, .bash_profile and .bashrc.

   Hint

   useradd -u 1500 -c 'Lena Berg' lena, then echo 'Redhat123!' | sudo passwd --stdin lena.

   Solution

   sudo useradd -u 1500 -c 'Lena Berg' lena
   echo 'Redhat123!' | sudo passwd --stdin lena
   id lena
   ls -A /home/lena

3. PracticeDone

   A service account that cannot log in

   Create a system account appsvc with no login shell, its home at /srv/appsvc (created), and a UID from the system range. Prove that logging in as it fails.

   Check your result

   id appsvc shows a UID below 1000. sudo su - appsvc prints This account is currently not available. and returns.

   Hint

   -r creates a system account, -s /sbin/nologin removes the login shell, -d and -m choose and create the home.

   Solution

   sudo useradd -r -s /sbin/nologin -d /srv/appsvc -m appsvc
   id appsvc
   sudo su - appsvc

4. PracticeDone

   Change, lock, then remove

   For lena: change her shell to /bin/zsh if installed, otherwise to /bin/sh; set the account to expire on 2027-01-31; lock it and show the lock is visible in /etc/shadow; unlock it; finally delete the account and her home directory.

   Check your result

   After locking, the password field in sudo grep lena /etc/shadow starts with !. After userdel -r, id lena fails with no such user and /home/lena is gone.

   Hint

   usermod -s, -e, -L, -U. userdel -r removes the home directory and mail spool.

   Solution

   sudo usermod -s /bin/sh lena
   sudo usermod -e 2027-01-31 lena
   sudo usermod -L lena
   sudo grep '^lena:' /etc/shadow
   sudo usermod -U lena
   sudo userdel -r lena
   id lena
   ls /home

5. ChallengeDone

   Onboard three users from a list

   Create users amy, ben and cho in one command sequence from this list, each with a comment equal to their capitalised name and the shell /bin/bash, all with the password Welcome#1. Do not type each useradd by hand. Verify all three exist and list their home directories.

   Check your result

   getent passwd amy ben cho prints three lines and ls -d /home/amy /home/ben /home/cho lists three directories.

   Hint

   A for loop over the names. ${name^} capitalises the first letter in bash.

   Solution

   for name in amy ben cho; do
     sudo useradd -c "${name^}" -s /bin/bash "$name"
     echo 'Welcome#1' | sudo passwd --stdin "$name"
   done
   getent passwd amy ben cho
   ls -d /home/amy /home/ben /home/cho