Grant sudo access in Debian and the Ubuntu operating system

This article provides the steps to grant an existing Linux® user sudo, or administravive, access on a Debian® server or a server with the Ubuntu® operating system.

Prerequisites

You need to have the following prerequisites:

• Basic understanding of Secure Shell (SSH)
• Sudo or administrative access to your server
• A Cloud Server running distributions based on Debian or the Ubuntu operating system.

Grant sudo or administrative permissions in Debian or the Ubuntu operating system

The following methods can be used to grant an existing user sudo-level permissions on a default Debian or Ubuntu operating system.

On a server with Debian or the Ubuntu operating system, the default group admin has sudo permissions. To add a user to this group and grant a user sudo permissions, run the following command:

   usermod -aG admin <user>

Run the following command to verify that you added the user to the admin group:

   id <user> 

If you added the user to the group successfully, you should see the admin group listed in the groups section.

Modify the sudoers file

Another method of granting sudo permissions on a Linux server is to modify the /etc/sudoers file to include the desired user. This method provides direct control by user rather than by adding a user to a group.

Warning: Editing the /etc/sudoers file might be destructive to the server, and the system might lock you out if there is any incorrect syntax in the file. Exercise caution when modifying this file.

To edit the /etc/sudoers file, we recommend that you use the visudo command.

After you open the file, add the following line to the end of the file:

   <user> ALL=(ALL)		ALL

After you make the change, save and exit the file. This modification grants the user sudo permissions without adding the user to the admin group.