We already have shown you how to create a sudo user, assign sudo permissions to existing users and remove sudo privileges from an user in Arch Linux, CentOS and Ubuntu. Today, we will see how to add, delete and grant sudo privileges to users in Alpine Linux.
For the purpose of this guide, I will be using a minimal Alpine Linux box.
Table of Contents
Add, Delete And Grant Sudo Privileges To Users In Alpine Linux
Login as root
user or any other existing sudo
user. Since it is a fresh and minimal Alpine Linux box, there are no other sudo users in my system, so I logged in as root
user.
First of all, make sure the sudo
package is installed in your Alpine Linux system. By default, sudo
is not installed.
To install sudo
in Alpine Linux as root
user, run:
$ sudo su
# apk update
# apk add sudo
Next, let us create a new user in Alpine Linux and grant sudo
privileges to the newly created user.
1. Create a sudo user in Alpine Linux
To create a new user in Alpine Linux, we use adduser
command as shown below:
# adduser ostechnix
Here, I am creating a new user named "ostechnix".
Enter the password twice for the new user and complete the user creation.
Changing password for ostechnix New password: Retype password: passwd: password for ostechnix changed by root
We have just created a new normal user. The user doesn't have any administrative rights yet.
You can verify if an user has sudo privileges or not in Alpine Linux using command:
# sudo -lU ostechnix
Replace "ostechnix" in the above example with you own username.
Sample output:
User ostechnix is not allowed to run sudo on alpine38.
Let us add the new user to sudoers list, so he/she can perform administrative operations.
1.1. Grant sudo privileges to users in Alpine Linux
We can do this in two ways.
Method 1 :
To assign sudo permissions to an user in Alpine Linux, simply add him/her to wheel
group. For those who don't know yet, wheel is a special group in some Unix-like operating systems. All the members of wheel
group can perform administrative tasks. Wheel group is similar to sudo
group in Debian-based systems.
Run the following command to allow the members of wheel
group to perform any command:
# echo '%wheel ALL=(ALL) ALL' > /etc/sudoers.d/wheel
Next, add the user "ostechnix" to the wheel
group:
# adduser ostechnix wheel
We added the user ostechnix to sudoers list. Now skip to the "1.2. Check if an user has sudo access in Alpine Linux" section and check if the user has sudo permissions.
Method 2:
The another way to assign sudo permissions to an user is by directly adding him in the /etc/sudoers
configuration file.
To give sudo permissions to the user "ostechnix", edit "/etc/sudoers"
file:
# visudo
Add the following line:
ostechnix ALL=(ALL) ALL
Hit ESC
key and type :wq
to save the file and exit.
Done! The user has been added to the sudoers list. Let su go ahead and check if he is able to run administrative operations.
1.2. Check if an user has sudo access in Alpine Linux
To verify if an user has sudo rights in Alpine Linux, run this command:
# sudo -lU ostechnix
Sample output:
User ostechnix may run the following commands on alpine38: (ALL) ALL
As you can see, the user "ostechnix" can run all commands in my Alpine Linux box.
Let us switch to the new sudo user and verify if he can able to run sudo tasks.
To switch to the new user i.e. ostechnix in our case, run:
# su - ostechnix
Run any sudo operation to verify if the user really has sudo permissions.
$ sudo apk update
Sample output:
Yes, the user has become part of the administrative users group.
2. Delete sudo privileges from an user in Alpine Linux
To revoke the sudo
permissions from an user in Alpine Linux, just remove him/her from the wheel
group using gpasswd
command. The gpasswd
command is not available in Alpine base image. You need to install shadow
package in order to get gpasswd
command.
To install shadow
package in Alpine Linux, run the following command as root
user:
# apk add shadow
Now you can remove the sudo
privileges from an user, for example ostechnix, using command:
# gpasswd -d ostechnix wheel
Sample output:
Removing user ostechnix from group wheel
The user ostechnix has been removed from wheel group. You can verify it using command:
# sudo -lU ostechnix
The user ostechnix has now become a regular user. He can't perform any sudo operations anymore.
If you don't want that user anymore, remove him entirely from the system using this command:
# userdel -r ostechnix
Here, -r
flag is used to delete the $HOME
directory of the user.
That's it. This tutorial taught you how to create a sudo user, and how to assign sudo privileges to existing users and finally how to delete the sudo privileges from an user in Alpine Linux. Hope it helps.