Day 20 ||Lab Task , User Management in Linux ||DevOps Bootcamp

User Management Basics

User management in Linux revolves around creating, modifying, and controlling user accounts on the system. This involves tasks such as creating new users, modifying user attributes, changing passwords, and more. Let's dive into each of these aspects.

Creating a User

To add a new user, use the useradd command:

sudo useradd username

For our lab task, we'll create a user named "labuser":

sudo useradd labuser

Setting User Password

Securing user accounts is paramount. To set a password for a user, use the passwd command:

sudo passwd username

For our lab task, set a password for "labuser":

sudo passwd labuser

Modifying User Attributes

User attributes such as the full name and home directory can be modified with the usermod command:

sudo usermod -c "Full Name" -d /new/home/directory username

Let's change the full name and home directory for "labuser":

sudo usermod -c "Lab User" -d /home/labuser labuser

Enabling and Disabling Users

You can temporarily disable a user account to prevent login without deleting it. Use the usermod command with the -L option to lock an account:

sudo usermod -L username

To unlock the account and enable it again, use the -U option:

sudo usermod -U username

For our lab task, we'll enable and disable the "labuser" account.

Changing a User's Default Shell

Linux users can have different default shells. To change a user's shell, use the chsh command:

sudo chsh -s /path/to/new/shell username

In the lab task, we'll change the default shell for "labuser" to /bin/bash.

Lab Task: Modifying User Attributes, Changing the Default Shell, and Enabling/Disabling Users

Objective: In this lab task, you will practice modifying user attributes, changing the default shell, and enabling/disabling user accounts.

Task 1: Modify User Attributes

Create a new user named "labuser" using the useradd command.
```
 sudo useradd labuser
```
Use the usermod command to change the full name and home directory of "labuser." Set the full name to "Lab User" and the home directory to "/home/labuser."
```
 sudo usermod -c "Lab User" -d /home/labuser labuser
```
Verify that the user attributes have been modified correctly by viewing the user's information in the /etc/passwd file.
```
 grep labuser /etc/passwd
```
Ensure that the output reflects the changes you made.

Task 2: Change Default Shell

Check the current default shell of "labuser" using the grep command:
```
 grep labuser /etc/passwd
```
Note the current shell (usually /bin/sh or /bin/bash).
Change the default shell of "labuser" to /bin/bash using the chsh command:
```
 sudo chsh -s /bin/bash labuser
```
Verify that the default shell has been changed by checking the user's information again in the /etc/passwd file:
```
 grep labuser /etc/passwd
```
Confirm that the shell has been updated to /bin/bash.

Task 3: Enable/Disable User Account

Disable the "labuser" account using the usermod command with the -L option:
```
 sudo usermod -L labuser
```
This will lock the account, preventing the user from logging in.
To re-enable the "labuser" account, use the usermod command with the -U option:
```
 sudo usermod -U labuser
```
This unlocks the account, allowing the user to log in again.

Task 4: Test the Changes

Switch to the "labuser" account using the su command:
```
 su - labuser
```
Verify that you can or cannot log in based on whether the account is enabled or disabled.