SLAPO-DYNLIST(5)

📦
version 2.7.2 · 24 versions
, in arch rolling

💖 SLAPO-DYNLIST 💖

okay bestie, welcome to slapo-dynlist(5) — the Dynamic List overlay for slapd. it's giving glue-that-makes-groups-glow. let's get into it 🦋

✨ NAME ✨

slapo-dynlist — Dynamic List overlay to slapd

✨ SYNOPSIS ✨

/etc/openldap/slapd.conf

✨ DESCRIPTION ✨

so the dynlist overlay plugs into slapd(8) and lets you expand dynamic lists and groups, which is honestly so iconic of it. here's the tea ☕: any time an entry with a specific objectClass (you define which one in the overlay config) is being returned, the LDAP URI-valued occurrences of a specific attribute (also defined in the overlay config, keep up 💅) get expanded into the corresponding entries.

For a dynamic list, the values of the attributes listed in the URI get added from the matching entries to the original entry. ngl there is no recursion allowed, and that's on purpose — we're avoiding potential infinite loops, we're not trying to crash the server fr fr. The resulting entry has to comply with the LDAP data model, so constraints are enforced. like, for example? if a SINGLE-VALUE attribute is listed, only the first value found during the list expansion shows up in the final entry. only the first. periodt.

For a dynamic group, the DNs of the matching entries get added to a member attribute in the original entry. cute, right? 🎀

and here's the plot twist: all dynamic behavior is disabled when the manageDSAit control (RFC 3296) is used. in that case you just get the contents of the original entry back — meaning the URLs are returned instead of being expanded. no expansion, no drama 🙈

✨ CONFIGURATION ✨

the config directives specific to the dynlist overlay must be prefixed by dynlist-, so we don't start beef with directives that belong to the underlying database or to other stacked overlays. keep the peace bestie 🕊️

  • overlay dynlist — this directive adds the dynlist overlay to the current database, or to the frontend if you use it before any database instantiation. see slapd.conf(5) for the deets.

This slapd.conf configuration option is defined for the dynlist overlay. It may have multiple occurrences, and it must appear after the overlay directive. (yes, order matters, she's particular 💅)

🧚 dynlist-attrset <group-oc> [<URI>] <URL-ad> [options]

  • the value group-oc is the name of the objectClass that triggers the dynamic expansion of the data. she's the main character of this expansion 💖
  • the optional URI restricts expansion only to entries matching the DN, the scope and the filter portions of the URI. selective, as she should be.
  • the value URL-ad is the name of the attributeDescription that contains the URI which gets expanded by the overlay. if none is present, no expansion occurs. and if the intersection of (a) the attributes requested by the search operation — or the asserted attribute for compares — and (b) the attributes listed in the URI is empty, then no expansion occurs for that specific URI. it must be a subtype of labeledURI.
  • the remaining options depend on whether you're configuring a dynamic list or a dynamic group.

🌸 for a dynamic list, the allowed options have the form

[<mapped-ad>:<list-ad> ...]
  • mapped-ad can be used to remap attributes obtained through expansion. iconic.
  • 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 — stack 'em up bestie.
  • > heads up: 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. no mapping, no filtering, no cap 🧢

🌈 for a dynamic group, the allowed options are

<member-ad>[+<memberOf-ad>[@<static-oc>[*]]]
  • 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 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. yes that's a mouthful, yes it's correct 💀
  • 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. don't do it. she will not handle it.
  • if the optional * character is also specified, then the member and memberOf values will be populated recursively, for nested groups. but — currently nesting is only supported for Search operations, not Compares. read that twice bestie 😭

🍓 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. (downstream, not upstream — she said what she said 💅)

✨ 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. no schema, no feature, that's the rule 🎀

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. don't forget it, she's needed ✨

✨ 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. everything. the whole closet 🫶

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 <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 <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

(the actual original line is: memberURL: ldap:///ou/People,dc=example,dc=com??sub?(objectClass=person) — copy it exactly, character for character, promise 🤞)

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 <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 <database>
# ...

overlay dynlist
dynlist-attrset groupOfURLs memberURL member+memberOf@groupOfNames

This dynamic memberOf feature can fully replace the functionality of the slapo-memberof(5) overlay. fully. replaced. slay 💅

✨ 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

future you says thanks for updating early 💖

✨ SEE ALSO ✨

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

✨ BUGS ✨

Filtering on dynamic groups may return incomplete results if the search operation uses the pagedResults control. yeah. that's the bug. she's aware 😭

✨ ACKNOWLEDGEMENTS ✨

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

Attribute remapping was contributed in 2008 by Emmanuel Dreyfus.

and that's the whole page, bestie — this manual page is from OpenLDAP 2.7.2, dated 2026/10/21, and honestly? ate. no crumbs. go configure something gorgeous 🌟💜

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