There are projects which provide daemons needing to be able to create, modify
and delete Unix users. Or just switch user ids to interact with the system e.g.
a user space file server. To be able to test that you need the privilege to
modify the passwd and groups file. With nss_wrapper it is possible to define
your own passwd and groups file which will be used by software to act correctly
while under test.

If you have a client and server under test they normally use functions to
resolve network names to addresses (dns) or vice versa. The nss_wrappers allow
you to create a hosts file to setup name resolution for the addresses you use
with socket_wrapper.

To use it set the following environment variables:

LD_PRELOAD=libuid_wrapper.so
NSS_WRAPPER_PASSWD=/path/to/passwd
NSS_WRAPPER_GROUP=/path/to/group
NSS_WRAPPER_HOSTS=/path/to/host

This package doesn't have a devel package cause this project is for
development/testing.