bionic (5) slapo-unique.5.gz

Provided by: slapd_2.4.45+dfsg-1ubuntu1.11_amd64 bug

NAME

       slapo-unique - Attribute Uniqueness overlay to slapd

SYNOPSIS

       /etc/ldap/slapd.conf

DESCRIPTION

       The  Attribute Uniqueness overlay can be used with a backend database such as slapd-bdb(5) to enforce the
       uniqueness of some or all attributes within a scope. This subtree defaults  to  all  objects  within  the
       subtree of the database for which the Uniqueness overlay is configured.

       Uniqueness  is  enforced  by  searching the subtree to ensure that the values of all attributes presented
       with an add, modify or modrdn operation are unique within the scope.  For  example,  if  uniqueness  were
       enforced for the uid attribute, the subtree would be searched for any other records which also have a uid
       attribute containing the same value. If any are found, the request is rejected.

       The search is performed using the rootdn of the database,  to  avoid  issues  with  ACLs  preventing  the
       overlay from seeing all of the relevant data. As such, the database must have a rootdn configured.

CONFIGURATION

       These slapd.conf options apply to the Attribute Uniqueness overlay.  They should appear after the overlay
       directive.

       unique_uri <[strict ][ignore ]URI[URI...]...>
              Configure the base, attributes, scope, and filter for uniqueness checking.  Multiple URIs  may  be
              specified within a domain, allowing complex selections of objects.  Multiple unique_uri statements
              or olcUniqueURI attributes will create independent domains, each with their own independent  lists
              of URIs and ignore/strict settings.

              Keywords strict and ignore have to be enclosed in quotes (") together with the URI.

              The LDAP URI syntax is a subset of RFC-4516, and takes the form:

              ldap:///[base dn]?[attributes...]?scope[?filter]

              The  base  dn  defaults  to  that of the back-end database.  Specified base dns must be within the
              subtree of the back-end database.

              If no attributes are specified, the URI applies to all non-operational attributes.

              The scope component is effectively mandatory, because LDAP URIs default to base  scope,  which  is
              not  valid  for  uniqueness,  because  groups of one object are always unique.  Scopes of sub (for
              subtree) and one for one-level are valid.

              The filter component causes the domain to apply uniqueness constraints only to  matching  objects.
              e.g.  ldap:///?cn?sub?(sn=e*) would require unique cn attributes for all objects in the subtree of
              the back-end database whose sn starts with an e.

              It is possible to assert uniqueness upon all non-operational attributes  except  those  listed  by
              prepending  the  keyword  ignore  If not configured, all non-operational (e.g., system) attributes
              must be unique. Note that the attributes list of  an  ignore  URI  should  generally  contain  the
              objectClass,  dc,  ou  and  o  attributes,  as  these  will  generally not be unique, nor are they
              operational attributes.

              It is possible to set strict checking for the uniqueness domain by prepending the keyword  strict.
              By  default,  uniqueness is not enforced for null values. Enabling strict mode extends the concept
              of uniqueness to include null values, such that only  one  attribute  within  a  subtree  will  be
              allowed to have a null value.  Strictness applies to all URIs within a uniqueness domain, but some
              domains may be strict while others are not.

       It is not possible to set both URIs and legacy slapo-unique configuration parameters  simultaneously.  In
       general, the legacy configuration options control pieces of a single unfiltered subtree domain.

       unique_base <basedn>
              This  legacy  configuration  parameter  should  be converted to the base dn component of the above
              unique_uri style of parameter.

       unique_ignore <attribute...>
              This legacy configuration parameter should be converted to  a  unique_uri  parameter  with  ignore
              keyword as described above.

       unique_attributes <attribute...>
              This  legacy  configuration  parameter should be converted to a unique_uri parameter, as described
              above.

       unique_strict <attribute...>
              This legacy configuration parameter should be  converted  to  a  strict  keyword  prepended  to  a
              unique_uri parameter, as described above.

CAVEATS

       unique_uri  cannot be used with the old-style of configuration, and vice versa.  unique_uri can implement
       everything the older system can do, however.

       Typical attributes for the ignore ldap:///...  URIs are intentionally not hardcoded into the  overlay  to
       allow for maximum flexibility in meeting site-specific requirements.

       Replication  and  operations  with  manageDsaIt  control  are  allowed  to bypass this enforcement. It is
       therefore important that all servers accepting writes have this overlay configured in order  to  maintain
       uniqueness in a replicated DIT.

FILES

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

SEE ALSO

       slapd.conf(5), slapd-config(5).