Binary package “libnss-ldap” in ubuntu bionic

NSS module for using LDAP as a naming service

 This package provides a Name Service Switch that allows your LDAP server
 act as a name service. This means providing user account information,
 group id's, host information, aliases, netgroups, and basically anything
 else that you would normally get from /etc flat files or NIS.
 .
 If used with glibc 2.1's nscd (Name Service Cache Daemon) it will help
 reduce your network traffic and speed up lookups for entries.