.. _LDAP:

LDAP integration

================

Overview

--------

Using LDAP as a source for user credentials and information is quite

easy. The most difficult part lies in building an LDAP schema or

using an existing one.

At cube creation time, one is asked if more sources are wanted. LDAP

is one possible option at this time. Of course, it is always possible

to set it up later using the `CWSource` entity type, which we discuss

there.

It is possible to add as many LDAP sources as wanted, which translates

in as many `CWSource` entities as needed.

The general principle of the LDAP source is, given a proper

configuration, to create local users matching the users available in

the directory and deriving local user attributes from directory users

attributes. Then a periodic task ensures local user information

synchronization with the directory.

Users handled by such a source should not be edited directly from

within the application instance itself. Rather, updates should happen

at the LDAP server level.

Credential checks are _always_ done against the LDAP server.

.. Note::

  There are currently two ldap source types: the older `ldapuser` and

  the newer `ldapfeed`. The older will be deprecated anytime soon, as

  the newer has now gained all the features of the old and does not

  suffer from some of its illnesses.

  The ldapfeed creates real `CWUser` entities, and then

  activate/deactivate them depending on their presence/absence in the

  corresponding LDAP source. Their attribute and state

  (activated/deactivated) are hence managed by the source mechanism;

  they should not be altered by other means (as such alterations may

  be overridden in some subsequent source synchronisation).

Configuration of an LDAPfeed source

-----------------------------------

Additional sources are created at cube creation time or later through the

user interface.

Configure an `ldapfeed` source from the user interface under `Manage` then

`data sources`:

* At this point `type` has been set to `ldapfeed`.

* The `parser` attribute shall be set to `ldapfeed`.

* The `url` attribute shall be set to an URL such as ldap://ldapserver.domain/.

* The `configuration` attribute contains many options. They are described in

  detail in the next paragraph.

Options of an LDAPfeed source

-----------------------------

Let us enumerate the options by categories (LDAP server connection,

LDAP schema mapping information).

LDAP server connection options:

* `auth-mode`, (choices are simple, cram_md5, digest_md5, gssapi, support

  for the later being partial as of now)

* `auth-realm`, realm to use when using gssapi/kerberos authentication

* `data-cnx-dn`, user dn to use to open data connection to the ldap (eg

  used to respond to rql queries)

* `data-cnx-password`, password to use to open data connection to the

  ldap (eg used to respond to rql queries)

If the LDAP server accepts anonymous binds, then it is possible to

leave data-cnx-dn and data-cnx-password empty. This is, however, quite

unlikely in practice. Beware that the LDAP server might hide attributes

such as "userPassword" while the rest of the attributes remain visible

through an anonymous binding.

LDAP schema mapping options:

* `user-base-dn`, base DN to lookup for users

* `user-scope`, user search scope (valid values: "BASE", "ONELEVEL",

  "SUBTREE")

* `user-classes`, classes of user (with Active Directory, you want to

  say "user" here)

* `user-filter`, additional filters to be set in the ldap query to

  find valid users

* `user-login-attr`, attribute used as login on authentication (with

  Active Directory, you want to use "sAMAccountName" here)

* `user-default-group`, name of a group in which ldap users will be by

  default. You can set multiple groups by separating them by a comma

* `user-attrs-map`, map from ldap user attributes to cubicweb

  attributes (with Active Directory, you want to use

  sAMAccountName:login,mail:email,givenName:firstname,sn:surname)

Other notes

-----------

* Cubicweb is able to start if ldap cannot be reached, even on

  cubicweb-ctl start ... If some source ldap server cannot be used

  while an instance is running, the corresponding users won't be

  authenticated but their status will not change (e.g. they will not

  be deactivated)

* The user-base-dn is a key that helps cubicweb map CWUsers to LDAP

  users: beware updating it

* When a user is removed from an LDAP source, it is deactivated in the

  CubicWeb instance; when a deactivated user comes back in the LDAP

  source, it (automatically) is activated again

* You can use the :class:`CWSourceHostConfig` to have variants for a source

  configuration according to the host the instance is running on. To do so

  go on the source's view from the sources management view.