usermod: group ‘sudo’ does not exist

It looks like you’re trying to add a user to the sudo group, but the group doesn’t exist on your system. This is common in some Linux distributions where the sudo group is not predefined. Here’s a detailed guide to fix this issue: Step-by-Step Guide

1. Check Existing Groups: First, let’s verify if the sudo group exists or if there’s an equivalent group like wheel:

   # cat /etc/group | grep sudo
   # cat /etc/group | grep wheel

1. Create the sudo Group (if it doesn’t exist): If the sudo group is not found, you can create it using:

   # sudo groupadd sudo

1. Add User to the sudo Group: Now, add your user (operationsuser) to the sudo group:

   # sudo usermod -aG sudo operationsuser

1. Configure Sudoers File: Edit the sudoers file to ensure the sudo group has the necessary permissions:

   # sudo visudo

Look for a line like this and uncomment it, if it’s not there, please add it (remove the # at the beginning):

   %sudo   ALL=(ALL:ALL) ALL

1. Verify the Changes: To ensure the changes take effect, you can check the user’s group memberships:

   # groups operationsuser

1. Test Sudo Access: Switch to the user and test if they have sudo access:

   > su -

The command should return a password prompt, provide your password and you should have root privileges. Alternative: Using the wheel Group In some distributions like CentOS, the wheel group is used instead of sudo. If you find the wheel group, you can add the user to it:

1. Add User to the wheel Group:

   # sudo usermod -aG wheel operationsuser

1. Configure Sudoers File: Edit the sudoers file:

   # sudo visudo

Ensure the following line is uncommented:

   %wheel  ALL=(ALL)       ALL

1. Verify and Test: Follow the same verification and testing steps as above.

This should resolve the issue and grant operationsuser the necessary sudo privileges. If you encounter any issues or have further questions, feel free to ask!