NAME

       slapo-dynlist - Dynamic List overlay to slapd

SYNOPSIS

       /etc/ldap/slapd.conf

DESCRIPTION

       The  dynlist  overlay  to slapd(8) allows expansion of dynamic groups and more.  Any time an entry with a
       specific objectClass (defined in the overlay  configuration)  is  being  returned,  the  LDAP  URI-valued
       occurrences  of  a  specific  attribute (also defined in the overlay configuration) are expanded into the
       corresponding entries, and the values of the attributes listed in the  URI  are  added  to  the  original
       entry.  No recursion is allowed, to avoid potential infinite loops.

       Since  the  resulting  entry  is dynamically constructed, it does not exist until it is constructed while
       being returned.  As a consequence, dynamically added attributes do not participate in the filter matching
       phase of the search request handling.  In other words, filtering for dynamically added attributes  always
       fails.

       The resulting entry must comply with the LDAP data model, so constraints are enforced.  For example, if a
       SINGLE-VALUE  attribute  is  listed,  only the first value found during the list expansion appears in the
       final entry.  The above described behavior is disabled when the manageDSAit control (RFC 3296)  is  used.
       In  that case, the contents of the dynamic group entry is returned; namely, the URLs are returned instead
       of being expanded.

CONFIGURATION

       The config directives that are specific to the dynlist overlay must be prefixed  by  dynlist-,  to  avoid
       potential conflicts with directives specific to the underlying database or to other stacked overlays.

       overlay dynlist
              This  directive  adds  the  dynlist  overlay  to the current database, or to the frontend, if used
              before any database instantiation; see slapd.conf(5) for details.

       This slapd.conf  configuration  option  is  defined  for  the  dynlist  overlay.  It  may  have  multiple
       occurrences, and it must appear after the overlay directive.

       dynlist-attrset <group-oc> [<URI>] <URL-ad> [[<mapped-ad>:]<member-ad> ...]
              The value group-oc is the name of the objectClass that triggers the dynamic expansion of the data.

              The  optional  URI  restricts  expansion only to entries matching the DN, the scope and the filter
              portions of the URI.

              The value URL-ad is the name of the attributeDescription that contains the URI that is expanded by
              the overlay; if none is present, no expansion occurs.   If  the  intersection  of  the  attributes
              requested  by  the  search  operation  (or the asserted attribute for compares) and the attributes
              listed in the URI is empty, no expansion occurs for that specific URI.  It must be  a  subtype  of
              labeledURI.

              The  value  member-ad  is  optional;  if  present,  the  overlay  behaves as a dynamic group: this
              attribute will list the DN of the entries resulting from the internal search.  In this  case,  the
              attrs  portion  of the URIs in the URL-ad attribute must be absent, and the DNs of all the entries
              resulting from the expansion of the URIs are listed as values of this  attribute.   Compares  that
              assert  the  value of the member-ad attribute of entries with group-oc objectClass apply as if the
              DN of the entries resulting from the expansion of the URI were present in the  group-oc  entry  as
              values of the member-ad attribute.

              Alternatively,  mapped-ad  can  be used to remap attributes obtained through expansion.  member-ad
              attributes are not filled by expanded DN, but are  remapped  as  mapped-ad  attributes.   Multiple
              mapping statements can be used.

       The  dynlist  overlay  may be used with any backend, but it is mainly intended for use with local storage
       backends.  In case the URI expansion is very resource-intensive and occurs frequently  with  well-defined
       patterns, one should consider adding a proxycache later on in the overlay stack.

AUTHORIZATION

       By  default  the expansions are performed using the identity of the current LDAP user.  This identity may
       be overridden by setting the dgIdentity attribute in the group's entry to the DN of  another  LDAP  user.
       In  that  case the dgIdentity will be used when expanding the URIs in the object.  Setting the dgIdentity
       to a zero-length string will cause the expansions to be performed anonymously.  Note that the  dgIdentity
       attribute  is  defined  in  the  dyngroup  schema,  and  this schema must be loaded before the dgIdentity
       authorization feature may be used.  If the dgAuthz attribute is also present in the  group's  entry,  its
       values  are  used  to determine what identities are authorized to use the dgIdentity to expand the group.
       Values of the dgAuthz attribute must conform to the (experimental) OpenLDAP authz syntax.

EXAMPLE

       This example collects all the email addresses of a database into a single entry; first of all, make  sure
       that slapd.conf contains the directives:

           include /path/to/dyngroup.schema
           # ...

           database <database>
           # ...

           overlay dynlist
           dynlist-attrset groupOfURLs memberURL

       and that slapd loads dynlist.la, if compiled as a run-time module; then add to the database an entry like

           dn: cn=Dynamic List,ou=Groups,dc=example,dc=com
           objectClass: groupOfURLs
           cn: Dynamic List
           memberURL: ldap:///ou=People,dc=example,dc=com?mail?sub?(objectClass=person)

       If no <attrs> are provided in the URI, all (non-operational) attributes are collected.

       This example implements the dynamic group feature on the member attribute:

           include /path/to/dyngroup.schema
           # ...

           database <database>
           # ...

           overlay dynlist
           dynlist-attrset groupOfURLs memberURL member

       A dynamic group with dgIdentity authorization could be created with an entry like

           dn: cn=Dynamic Group,ou=Groups,dc=example,dc=com
           objectClass: groupOfURLs
           objectClass: dgIdentityAux
           cn: Dynamic Group
           memberURL: ldap:///ou=People,dc=example,dc=com??sub?(objectClass=person)
           dgIdentity: cn=Group Proxy,ou=Services,dc=example,dc=com

FILES

       /etc/ldap/slapd.conf
              default slapd configuration file

SEE ALSO

       slapd.conf(5),  slapd-config(5),  slapd(8).   The slapo-dynlist(5) overlay supports dynamic configuration
       via back-config.

ACKNOWLEDGEMENTS

       This module was written in 2004 by Pierangelo Masarati for SysNet s.n.c.

       Attribute remapping was contributed in 2008 by Emmanuel Dreyfus.

OpenLDAP                                           2020/01/30                                   SLAPO-DYNLIST(5)