--- name: "slapo-dynlist" section: "5" platform: "linux" package: "openldap" version: "2.7.2-2" release: "Arch Linux 2026-11-01" platforms: ["linux", "macos"] url: "https://new.carta.tech/slapo-dynlist" --- # slapo-dynlist(5) Dynamic List overlay to slapd ## NAME slapo-dynlist - Dynamic List overlay to slapd ## SYNOPSIS /etc/openldap/slapd.conf ## DESCRIPTION The **dynlist** overlay to [**slapd**(8)](/slapd/8.md) allows expansion of dynamic lists and groups. 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. For a dynamic list, the values of the attributes listed in the URI are added from the matching entries to the original entry. No recursion is allowed, to avoid potential infinite loops. 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. For a dynamic group, the DNs of the matching entries are added to a member attribute in the original entry. All dynamic behavior is disabled when the *manageDSAit* control (RFC 3296) is used. In that case, the contents of the original 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)](/slapd.conf/5.md) 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 \ \[\\] \ \[options\]** 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 remaining options depend on whether a dynamic list or a dynamic group is being configured. For a dynamic list, the allowed options have the form **\[\:\ ...\]** The **mapped-ad** can be used to remap attributes obtained through expansion. The **list-ad** must be one of the attributes returned in the expansion of the URIs in the **URL-ad** attribute of the dynamic entry. Multiple mapping statements can be used. Note that in order for dynamic lists to be usable in a search filter, the dynamic attributes to be filtered must be explicitly mapped. They can be mapped to themselves if no transformation is required. For a dynamic group, the allowed options are **\\[+\\[@\\[\*\]\]\]** The **member-ad** is required; 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 *DN*s 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. If the optional **memberOf-ad** attribute is also specified, then it will be populated with the DNs of the dynamic groups that an entry is a member of. If the optional **static-oc** objectClass is also specified, then the memberOf attribute will also be populated with the DNs of the static groups that an entry is a member of. Note that using the same **static-oc** objectClass in more than one dynamic group configuration is not supported. If the optional **\*** character is also specified, then the member and memberOf values will be populated recursively, for nested groups. Note that currently nesting is only supported for Search operations, not Compares. - **dynlist-simple TRUE \| FALSE** This option downgrades to the behavior of the OpenLDAP 2.4 dynlist overlay. It disables memberOf processing, nested group support, and filter evaluation of dynamically generated values. The default is FALSE. 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. When using dynamic memberOf in search filters, search access to the **entryDN** pseudo-attribute is required. ## 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 # ... 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 \ are provided in the URI, all (non-operational) attributes are collected. The values of the above list can not be evaluated in a search filter. To enable filter evaluation on the dynamic list, the configuration must be changed to explicitly map the dynamic attributes to be filtered. In this case **mail** is just mapped to itself. ``` include /path/to/dyngroup.schema # ... database # ... overlay dynlist dynlist-attrset groupOfURLs memberURL mail:mail ``` This example implements the dynamic group feature on the **member** attribute: ``` include /path/to/dyngroup.schema # ... 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 ``` This example extends the dynamic group feature to add a dynamic **dgMemberOf** attribute to all the members of a dynamic group: ``` include /path/to/dyngroup.schema # ... database # ... overlay dynlist dynlist-attrset groupOfURLs memberURL member+dgMemberOf ``` This example extends the dynamic memberOf feature to add the **memberOf** attribute to all the members of both static and dynamic groups: ``` include /path/to/dyngroup.schema # ... database # ... overlay dynlist dynlist-attrset groupOfURLs memberURL member+memberOf@groupOfNames ``` This dynamic memberOf feature can fully replace the functionality of the [**slapo-memberof**(5)](/slapo-memberof/5.md) overlay. ## FILES - /etc/openldap/slapd.conf default slapd configuration file ## BACKWARD COMPATIBILITY The dynlist overlay has been reworked with the 2.5 release to use a consistent namespace as with other overlays. As a side-effect the following cn=config parameters are deprecated and will be removed in a future release: **olcDlAttrSet** is replaced with olcDynListAttrSet **olcDynamicList** is replaced with olcDynListConfig ## SEE ALSO [**slapd.conf**(5)](/slapd.conf/5.md), [**slapd-config**(5)](/slapd-config/5.md), [**slapd**(8)](/slapd/8.md). The [**slapo-dynlist**(5)](/slapo-dynlist/5.md) overlay supports dynamic configuration via **back-config**. ## BUGS Filtering on dynamic groups may return incomplete results if the search operation uses the *pagedResults* control. ## ACKNOWLEDGEMENTS This module was written in 2004 by Pierangelo Masarati for SysNet s.n.c. Attribute remapping was contributed in 2008 by Emmanuel Dreyfus.