How to Add User to Sudoers or Sudo Group on Ubuntu (phoenixnap.com)

How to Add User to Sudoers or Sudo Group on Ubuntu (phoenixnap.com)

How to Add User to Sudoers or Sudo Group on Ubuntu

 

Introduction

The sudo command is the preferred means to handle elevated permissions. In supported versions of Ubuntu, using the sudo command will grant elevated permissions for 15 minutes.

Standard user accounts are restricted from performing sensitive tasks, such as viewing the contents of the /root directory. This prevents the accidental use of commands with massive consequences. It also makes it more difficult for intruders to compromise a system. However, sometimes you need to run an administrative command. Sudo – or Super User Do – grants you privileges to run sensitive tasks.

This simple tutorial will show you how to add a new user on Ubuntu and provide sudo access.

Prerequisites

• A system running a supported version of Ubuntu
• Access to a root user account or another account with sudo privileges
• Access to a terminal window/command line (Ctrl–Alt–T)

 

Note: Linux Sudo Command tutorials also available for CentOS and Debian.

Steps to Add Sudo User on Ubuntu

Step 1: Create New User

1. Log into the system with a root user or an account with sudo privileges.

2. Open a terminal window and add a new user with the command:

adduser newuser

The adduser command creates a new user, plus a group and home directory for that user.

You may get an error message that you have insufficient privileges. (This typically only happens for non-root users.) Get around it by entering:

sudo adduser newuser

3. You can replace newuser with any username you wish. The system will add the new user; then prompt you to enter a password. Enter a great secure password, then retype it to confirm.

4. The system will prompt you to enter additional information about the user. This includes a name, phone numbers, etc. – these fields are optional, and can be skipped by pressing Enter.

Step 2: Add User to Sudo Group

Most Linux systems, including Ubuntu, have a user group for sudo users. To grant the new user elevated privileges, add them to the sudo group.

In a terminal, enter the command:

usermod -aG sudo newuser

Replace newuser with the username that you entered in Step 1.

Again, if you get an error, run the command with sudo as follows:

sudo usermod -aG sudo newuser

The -aG option tells the system to append the user to the specified group. (The -a option is only used with G.)

 

Note: Usermod command is a useful tool for user management. To learn more about its options, refer to our guide How To Use The Usermod Command In Linux.

Step 3: Verify User Belongs to Sudo Group

Enter the following to view the groups a user belongs to:

groups newuser

The system will respond by listing the username and all groups it belongs to, for example: newuser : newuser sudo

Step 4: Verify Sudo Access

Switch users by entering:

su - newuser

Replace newuser with the username you entered in Step 1. Enter your password when prompted. You can run commands as normal, just by typing them.

For example:

ls /home

However, some commands or locations require elevated privileges. If you try to list the contents of the /root directory, you’ll get an access denied error: ls /root

The command can be executed with:

sudo ls /root

The system will prompt for your password. Use the same password you set in Step 1. You should now see the contents of the /root directory.

Conclusion

Now you know how to add and create a user with sudo privileges on Ubuntu.

Before sudo, users would log in to their systems with full permissions over the entire system with the su command. This was risky as users could be exploited by tricking them into entering malicious commands. These vulnerabilities were solved by limiting account privileges. However, administrators still had to log out of their account and into an admin account to perform routine tasks.

The sudo command in Ubuntu strikes a balance – protecting user accounts from malicious or inadvertent damage while allowing a privileged user to run administrative tasks. To learn more about the difference between these commands, check out Sudo vs. Su.