libnss-ato (Name Service Switch module All-To-One)

The libnss_ato module is a set of C library extensions which allows to map every nss request for unknown user to a single predefined user.

Description

Suppose your system has only one account (apart from root and system users) named user_test:

]$ id user_test
]$ uid=1000(user_test) gid=1000 groups=1000

If you add libnss-ato to the chain of nss modules (in /etc/nsswitch.conf) you get something like:

]$ id randomname
]$ uid=1000(user_test) gid=1000 groups=1000

for every query of a random username not present in /etc/passwd.

Why?

This module can be used for pubblic workstations where you only need to verify username / password from a pam module (for example pam-krb5 for Active Directory users) and there is no need to give the user his own uid, gid or homedir

Installation

From source just make and make install.

The only configuration file is /etc/libnss-ato.conf which consists of one line in the passwd format. For example:

test_user:x:1000:1000:Test User�,:/home/test:/bin/bash

Only the first line of the file /etc/libnss-ato.conf is parsed.

Here an example of the system file /etc/nsswitch.conf to make use of libnss-ato:

passwd:         files ato
group:          files
shadow:         files ato