SLAPO-DYNLIST(5)                       File Formats Manual                       SLAPO-DYNLIST(5)



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  con‐
       structed while being returned.  As a consequence, dynamically added attributes do not par‐
       ticipate 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 dyn‐
       list-, 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 fron‐
              tend, 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  mul‐
       tiple 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 expan‐
              sion 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 inter‐
              section  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 mem‐
              ber-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  expan‐
              sion.   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 dyn‐
       group 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 data‐
       base 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                                    2014/09/20                           SLAPO-DYNLIST(5)