Examples are provided below, for both ``form_login_ldap`` and

``http_basic_ldap``.

query_string

**type**: ``string`` **default**: ``null``

This optional key defines the form of the query used in order to search the

DN of the user, from the username. The ``{username}`` string is replaced by

the actual username of the person trying to authenticate.

This setting is only necessary if the users DN cannot be derived statically

using the `dn_string` config option.

Configuration example for form login