Creating a New Non-root Linux User

Summary

We are going to create a non-root user that has the same privileges of a root user—we create this type of user because using the root user can end in disaster with a few bad keystrokes.  We are mitigating these risks by creating a non-root user.  Further, with a non-root user, we can still grant sudo privileges so that we are only executing these sudo commands when necessary and not at all times.  Finally, if you are making this machine a central part of your data science workbench, then you can create new user accounts and grant access to some files, directories and applications as you see fit.

Requirements

The following requirements are necessary for successfully completing this tutorial:

• Read & Complete steps in the "Standing Up a Linux Server" Post 

Learning Objectives

The following learning objectives are intended to describe what elements will be tackled in this section along with how and why we are doing it this way.

• Create a sudo, non-root user in a Linux Ubuntu 18.04 virtual environment
• Disable remote access via SSH to the root user

Implementation

You should be at a point where you are logged into your new instance as a root user—we are going to create a new user called alpha in this case, grant sudo privileges to this user and then disable our root account.  Finally, we will test the solution by logging out and logging back in using only the new user, alpha.

Let's follow the commands below to get things rolling (screenshots follow below):

You'll now enter a new password, confirm this password, enter some additional information and confirm it all.  Now let's give this user the proper sudo privileges and then start using that account:

Now we can log out of the service and our SSH session and try logging back in using the following commands:

Great, so this should have worked!  Let's now adjust some of the system settings to disable the root login using the `vim` text editor:

While in this file, go ahead and update the following first line and add the next line to the file—you can naivgate within the vim editor using the arrows on your keyboard, typing the "i" button to begin inserting text, and typing the following series of commands to save and exit the vim editor while persisting your changes ("esc" + ":" + "wq" + "enter"):

Now let's restart a few processes so that thes echanges go into effect:

Now if you log out of the server, then you should not be able to log back in using your original root account, but should still be able to log in using your new alpha account.

Mission completed?

Cheers, JAH!