Install libnss-wrapper by entering the following commands in the terminal:
sudo apt update sudo apt install libnss-wrapper
NSS wrapper library
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, for example 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.