To make LemonLDAP::NG work with SELinux, you may need to set up some options.
chcon -R -t httpd_sys_rw_content_t /tmp
To persist the rule:
semanage fcontext -a -t http_sys_content_t /tmp
setsebool -P httpd_can_connect_ldap 1
setsebool -P httpd_can_network_connect_db 1
setsebool -P httpd_can_network_memcache 1
setsebool -P httpd_can_network_relay 1