Linux Command Linx

Creating a New Linux User

With Super-User permission

Introduction

Linux is a multi-user operating system and as such can support multiple users. In this brief tutorial, we show how to(1) create a user, (2) give him super-user privileges if needed, and finally (3) allow him to connect to the machine using ssh if remote access is required.

Add New User

The command to use is:

adduser <username>

Remember the “add” at the beginning. Don’t confuse this command with the “useradd” command.

Add the user to groups (Super-User group)

You may want to add the new user to a few groups. The most important group is “sud o” (supposing you want to give him the superuser permission).

sudo usermod -aG sudo <username>

Once granted, the user can add himself to other groups if needed.

Add the user to groups (self)

Once the user has super-user privileges (“sudo”) and is logged in, he/she should use this command to add itself to other groups.

sudo usermod -aG <groupname> <username>
newgrp <groupname>

For example to add itself to the docker group (necessary to run docker without the sudo):

sudo usermod -aG docker <username>
newgrp docker

Add SSH Connection

If the target machine is a server that supports connection only through ssh-key. Put the user ssh public key in “/home/<username>/.ssh/authorized_keys” file.

echo "<public key>" > /home/<username>/.ssh/authorized_keys

<username>: is the user’s alias

To create the couple of private and public keys, run the command

ssh-keygen

Conclusion

This is it for today's tutorial, feel free to comment or ask any questions. And don’t forget to clap and follow ;)