slapo−translucent — Translucent Proxy overlay to slapd
ETCDIR/slapd.conf
The Translucent Proxy overlay can be used with a backend database such as slapd-bdb(5) to create a "translucent proxy". Entries retrieved from a remote LDAP server may have some or all attributes overridden, or new attributes added, by entries in the local database before being presented to the client.
A search
operation is first populated with entries from the remote
LDAP server, the attributes of which are then overridden with
any attributes defined in the local database. Local overrides
may be populated with the add, modify , and modrdn operations, the use of
which is restricted to the root user.
A compare
operation will perform a comparison with attributes defined
in the local database record (if any) before any comparison
is made with data in the remote database.
The Translucent Proxy overlay uses a proxied database,
typically a (set of) remote LDAP server(s), which is
configured with the options shown in slapd-ldap(5), slapd-meta(5) or similar.
These slapd.conf
options are specific to the Translucent Proxy overlay; they
must appear after the overlay directive that
instantiates the translucent overlay.
translucent_strictBy default, attempts to delete attributes in either
the local or remote databases will be silently ignored.
The translucent_strict
directive causes these modifications to fail with a
Constraint Violation.
translucent_no_glueThis configuration option disables the automatic
creation of "glue" records for an add or modrdn operation, such
that all parents of an entry added to the local
database must be created by hand. Glue records are
always created for a modify operation.
Specify a list of attributes that should be searched for in the local database when used in a search filter. By default, search filters are only handled by the remote database. With this directive, search filters will be split into a local and remote portion, and local attributes will be searched locally.
Specify a list of attributes that should be searched
for in the remote database when used in a search
filter. This directive complements the translucent_local
directive. Attributes may be specified as both local
and remote if desired.
If neither translucent_local nor
translucent_remote
are specified, the default behavior is to search the remote
database with the complete search filter. If only translucent_local is
specified, searches will only be run on the local database.
Likewise, if only translucent_remote is
specified, searches will only be run on the remote database.
In any case, both the local and remote entries corresponding
to a search result will be merged before being returned to
the client.
translucent_bind_localEnable looking for locally stored credentials for simple bind when binding to the remote database fails. Disabled by default.
translucent_pwmod_localEnable RFC 3062 Password Modification extended operation on locally stored credentials. The operation only applies to entries that exist in the remote database. Disabled by default.
Access control is delegated to either the remote DSA(s) or
to the local database backend for auth and write operations. It is
delegated to the remote DSA(s) and to the frontend for
read operations.
Local access rules involving data returned by the remote
DSA(s) should be designed with care. In fact, entries are
returned by the remote DSA(s) only based on the remote
fraction of the data, based on the identity the operation is
performed as. As a consequence, local rules might only be
allowed to see a portion of the remote data.
The Translucent Proxy overlay will disable schema checking in the local database, so that an entry consisting of overlay attributes need not adhere to the complete schema.
Because the translucent overlay does not perform any DN rewrites, the local and remote database instances must have the same suffix. Other configurations will probably fail with No Such Object and other errors.