User Management¶

Creating a user¶

For this course let's create a user named ansibleuser with the default home directory

Adding a user with useradd¶

On the server1 we'll use the more manual useradd cli

sudo useradd -m ansibleuser

-m creates a home directory for the user in the default location

Set a password a user¶

Change the password for ansibleuser

sudo passwd ansibleuser

New password: 
Retype new password:
passwd: password updated successfully

Add a user using adduser¶

On server2, we can use the more user friendly adduser cli. It will automatically create a home directory and group memberships and prompt for a password to be set.

sudo adduser anisbleuser

Adding user `ansibleuser' ...
Adding new group `ansibleuser' (1004) ...
Adding new user `ansibleuser' (1004) with group `ansibleuser' ...
Creating home directory `/home/ansibleuser' ...
Copying files from `/etc/skel' ...
New password:
Retype new password:
passwd: password updated successfully
Changing the user information for ansibleuser
Enter the new value, or press ENTER for the default
        Full Name []: Ansible User
        Room Number []:
        Work Phone []:
        Home Phone []:

        Other []:
Is the information correct? [Y/n] y

Create a group¶

Permissions can be assigned to individual users or to groups.

Create a group that will be used in a later lesson

On both servers, create the group

sudo groupadd courseadmin

Add user to group with usermod¶

On server1, add the pluser user to the new courseadmin group

sudo usermod -aG courseadmin pluser

-a to append the user to supplemental GROUPS mentioned by the -G option without removing the user from other groups

-G specifies the group to add, and that the group is not the user's primary group

Add user to group with usermod¶

You can also use the adduser command to add a user to a group

On the server2 run the following command

sudo adduser pluser courseadmin

Move the home directory for a user¶

This is not something we need to do for the course but might be needed eventually.

A user's home directory can be changed at any time.

sudo usermod -m -d /usr/testuser testuser

-m will move the existing content, if any, from the current home folder to the new home folder, /usr/testuser, for the user 'testuser'

You see every user's current home directory in the passwd file

cat /etc/passwd

passwd

...
pluser:x:1001:1001:,,,:/home/pluser:/bin/bash
...

<username>:<placeholder for password>:<UID>:<GID>:<Full Name,Room Number,Work Phone,Home Phone>:<home directory>:<shell>

Change a user's shell¶

The default shell on Ubuntu is bash but user's can use many different shells.

To set a user's default shell, we can use the chsh commnand but first we need to know which shells are installed on the server

cat /etc/shells

Copy the full path of the shell you want to set

sudo chsh ansibleuser

Changing the login shell for ansibleuser
Enter the new value, or press ENTER for the default
        Login Shell [/bin/bash]: /bin/sh

Every user's current shell is also listed in the passwd file

cat /etc/passwd