How to remove traces of a deleted user

Question

I have been tasked with removing departed employees' local *nix accounts. In almost all cases, userdel -r <username> works like a charm. However there are a few cases where the user in question was removed uncleanly on a prior date, leaving their account non-existent but with a presence in the /etc/group file and a home directory. When the task comes to me to remove their user from the system, I find that the user doesn't exist, but I still need to remove these remnants. In this case, userdel -r <username> prints userdel: user '<username>' does not exist, and the orphaned group entries, mail spool, home directory etc are not removed.

I could whip up a script to check home, group, and mail spool myself, but I'd rather use an existing utility if it exists. That utility can be a shell command or an Ansible module.

I'm given the username to purge, and that can be assumed correct, though case insensitivity would be a bonus. If there's a safe way to find and correct all non-existent users without an input, that would be even better, as it would save me from having to rework previous tasks.

Answer 1

What I understand is that you need to delete the user from all his secondary groups with a core utility (on top of userdel)

usermod -G "" <username> && userdel -r <username>

You could add it as function to your ~/.bash_aliases or ~/.bashrc for quicker use

nukeusr() {
    usermod -G \"\" $1 && userdel -r $1
}

Then nukeusr <username> to delete the user from the groups too.