From Antiflux Wiki
Find a user by username
ldapsearch -x uid=«username»
Add a record
ldapadd -xW -D cn=admin,dc=antiflux,dc=org < «file.ldif»
Copy user from /etc/passwd to LDAP
sudo ldif-from-password «username» | ldapadd -xW -D cn=admin,dc=antiflux,dc=org