================================================= Common LDAP operation (for YunoHost but not only) ================================================= Moulinette is deeply integrated with LDAP which is used for a series of things like: * storing users * storing domains (for users emails) * SSO This page document how to uses it on a programming side in YunoHost. Getting access to LDAP in a command =================================== To get access to LDAP you need to authenticate against it, for that you need to declare your command with requiring authentication in the :ref:`actionsmap` this way: :: configuration: authenticate: all Here is a complete example: :: somecommand: category_help: .. actions: ### somecommand_stuff() stuff: action_help: ... api: GET /... configuration: authenticate: all This will prompt the user for a password in CLI. If you only need to **read** LDAP (and not modify it, for example by listing domains), then you prevent the need for a password by using the :file:`ldap-anonymous` authenticator this way: :: configuration: authenticate: all authenticator: ldap-anonymous Once you have declared your command like that, your python function will received the :file:`auth` object as first argument, it will be used to talk to LDAP, so you need to declare your function this way: :: def somecommand_stuff(auth, ...): ... auth in the moulinette code --------------------------- The :file:`auth` object is an instance of :file:`moulinette.authenticators.ldap.Authenticator` class. Here its docstring: .. autoclass:: moulinette.authenticators.ldap.Authenticator LDAP Schema =========== This is a generated example of the ldap schema provided by YunoHost (to generate this graph uses :file:`make ldap_graph`, you'll need graphviz): .. image:: ldap_graph.png Reading from LDAP ================= Reading data from LDAP is done using the :file:`auth` object received as first argument of the python function. To see how to get this object read the previous section. The API looks like this: :: auth.search(ldap_path, ldap_query) This will return a list of dictionary with strings as keys and list as values. You can also specify a list of attributes you want to access from LDAP using a list of string (on only one string apparently): :: auth.search(ldap_path, ldap_query, ['first_attribute', 'another_attribute']) For example, if we request the user :file:`alice` with its :file:`homeDirectory`, this would look like this: :: auth.search('ou=users,dc=yunohost,dc=org', '(&(objectclass=person)(uid=alice))', ['homeDirectory', 'another_attribute']) And as a result we will get: :: [{'homeDirectory': ['/home/alice']}] Notice that even for a single result we get a **list** of result and that every value in the dictionary is also a **list** of values. This is not really convenient and it would be better to have a real ORM, but for now we are stuck with that. Apparently if we don't specify the list of attributes it seems that we get all attributes (need to be confirmed). Here is the method docstring: .. automethod:: moulinette.authenticators.ldap.Authenticator.search Users LDAP schema ----------------- According to :file:`ldapvi` this is the user schema (on YunoHost >3.7): :: # path: uid=the_unix_username,ou=users,dc=yunohost,dc=org uid: the_unix_username objectClass: mailAccount objectClass: inetOrgPerson objectClass: posixAccount objectClass: userPermissionYnh loginShell: /bin/false uidNumber: 80833 maildrop: the_unix_username # why? cn: first_name last_name displayName: first_name last_name mailuserquota: some_value gidNumber: 80833 sn: last_name homeDirectory: /home/the_unix_username mail: the_unix_username@domain.com # if the user is the admin he will also have the following mails mail: root@domain.com mail: admin@domain.com mail: webmaster@domain.com mail: postmaster@domain.com givenName: first_name memberOf: cn=the_unix_username,ou=groups,dc=yunohost,dc=org memberOf: cn=all_users,ou=groups,dc=yunohost,dc=org permission: cn=main.mail,ou=permission,dc=yunohost,dc=org permission: cn=main.metronome,ou=permission,dc=yunohost,dc=org The admin user is a special case that looks like this: :: # path: cn=admin,dc=yunohost,dc=org gidNumber: 1007 cn: admin homeDirectory: /home/admin objectClass: organizationalRole objectClass: posixAccount objectClass: simpleSecurityObject loginShell: /bin/bash description: LDAP Administrator uidNumber: 1007 uid: admin Other user related schemas: :: # path: cn=admins,ou=groups,dc=yunohost,dc=org objectClass: posixGroup objectClass: top memberUid: admin gidNumber: 4001 cn: admins # path: cn=admin,ou=sudo,dc=yunohost,dc=org # this entry seems to specify which unix user is a sudoer cn: admin sudoCommand: ALL sudoUser: admin objectClass: sudoRole objectClass: top sudoOption: !authenticate sudoHost: ALL Reading users from LDAP ----------------------- The user schema is located at this path: :file:`ou=users,dc=yunohost,dc=org` According to already existing code, the queries we uses are: * :file:`'(&(objectclass=person)(!(uid=root))(!(uid=nobody)))'` to get all users (not that I've never encountered users with :file:`root` or :file:`nobody` uid in the ldap database, those might be there for historical reason) * :file:`'(&(objectclass=person)(uid=%s))' % username` to access one user data This give us the 2 following python calls: :: # all users auth.search('ou=users,dc=yunohost,dc=org', '(&(objectclass=person)(!(uid=root))(!(uid=nobody)))') # one user auth.search('ou=users,dc=yunohost,dc=org', '(&(objectclass=person)(uid=some_username))') Apparently we could also access one user using the following path (and not query): :file:`uid=user_username,ou=users,dc=yunohost,dc=org` but I haven't test it. If you want specific attributes look at the general documentation on how to read from LDAP a bit above of this section. Group LDAP schema ----------------- According to :file:`ldapvi` this is the user schema (on YunoHost >3.4): The groups will look like this: :: dn: cn=the_unix_username,ou=groups,dc=yunohost,dc=org objectClass: top objectClass: groupOfNamesYnh objectClass: posixGroup gidNumber: 48335 cn: the_unix_username structuralObjectClass: posixGroup member: uid=the_unix_username,ou=users,dc=yunohost,dc=org By default you will find in all case a group named `all_users` which will contains all Yunohost users. :: # path dn: cn=all_users,ou=groups,dc=yunohost,dc=org objectClass: posixGroup objectClass: groupOfNamesYnh gidNumber: 4002 cn: all_users structuralObjectClass: posixGroup permission: cn=main.mail,ou=permission,dc=yunohost,dc=org permission: cn=main.metronome,ou=permission,dc=yunohost,dc=org member: uid=the_unix_username,ou=users,dc=yunohost,dc=org memberUid: the_unix_username Reading group from LDAP ----------------------- The group schema is located at this path: :file:`ou=groups,dc=yunohost,dc=org` The queries we uses are the 2 following python calls: :: # all groups auth.search('ou=groups,dc=yunohost,dc=org', '(objectclass=groupOfNamesYnh)') # one groups auth.search(base='ou=groups,dc=yunohost,dc=org', filter='cn=' + groupname) Permission LDAP schema ---------------------- According to :file:`ldapvi` this is the user schema (on YunoHost >3.4): The permission will look like this: :: dn: cn=main.mail,ou=permission,dc=yunohost,dc=org objectClass: posixGroup objectClass: permissionYnh gidNumber: 5001 groupPermission: cn=all_users,ou=groups,dc=yunohost,dc=org cn: main.mail structuralObjectClass: posixGroup memberUid: the_unix_username inheritPermission: uid=the_unix_username,ou=users,dc=yunohost,dc=org By default you will have a permission for the mail and for metronome. When you install an application a permission also created. Reading permissions from LDAP ----------------------------- The permission schema is located at this path: :file:`ou=permission,dc=yunohost,dc=org` The queries we uses are the 2 following python calls: :: # For all permission auth.search('ou=permission,dc=yunohost,dc=org', '(objectclass=permissionYnh)') # For one permission auth.search(base='ou=permission,dc=yunohost,dc=org', filter='cn=' + permission_name) Domain LDAP schema ------------------ According to :file:`ldapvi` this is the domain schema (on YunoHost 2.7): :: 10 virtualdomain=domain.com,ou=domains,dc=yunohost,dc=org objectClass: mailDomain objectClass: top virtualdomain: domain.com Adding data in LDAP =================== If you add an object linked to user, group or permission you need run the function `permission_sync_to_user` to keep integrity of permission in LDAP. Adding stuff in LDAP seems pretty simple, according to existing code it looks like this: :: auth.add('key=%s,ou=some_location', {'attribute1': 'value', ...}) They weird stuff is the path you need to create. This looks like that for domain and users: :: # domain auth.add('virtualdomain=%s,ou=domains' % domain, attr_dict) # user auth.add('uid=%s,ou=users' % username, attr_dict) You need to respect the expected attributes. Refer to the schema for that. :file:`auth.add` seems to return something false when it failed (None probably) so you need to check it's return code. Here is the docstring: .. automethod:: moulinette.authenticators.ldap.Authenticator.add Adding user in LDAP ------------------- Here is how it's done for a new user: :: auth.add('uid=%s,ou=users' % username, { 'objectClass': ['mailAccount', 'inetOrgPerson', 'posixAccount'], 'givenName': firstname, 'sn': lastname, 'displayName': '%s %s' % (firstname, lastname), 'cn': fullname, 'uid': username, 'mail': mail, 'maildrop': username, 'mailuserquota': mailbox_quota, 'userPassword': user_pwd, 'gidNumber': uid, 'uidNumber': uid, 'homeDirectory': '/home/' + username, 'loginShell': '/bin/false' }) Adding a domain in LDAP ----------------------- Here is how it's done for a new domain: :: auth.add('virtualdomain=%s,ou=domains' % domain, { 'objectClass': ['mailDomain', 'top'] 'virtualdomain': domain, }) Updating LDAP data ================== If you add an object linked to user, group or permission you need run the function `permission_sync_to_user` to keep integrity of permission in LDAP. Update a user from LDAP looks like a simplified version of searching. The syntax is the following one: :: auth.update(exact_path_to_object, {'attribute_to_modify': 'new_value', 'another_attribute_to_modify': 'another_value', ...}) For example this will update a user :file:`loginShell`: :: auth.update('uid=some_username,ou=users', {'loginShell': '/bin/bash'}) I don't know how this call behave if it fails and what it returns. Here is the method docstring: .. automethod:: moulinette.authenticators.ldap.Authenticator.update Updating a user in LDAP ------------------------- This is done this way: :: auth.update('uid=some_username,ou=users', {'attribute': 'new_value', ...}) Refer to the user schema to know which attributes you can modify. Validate uniqueness =================== There is a method to validate the uniqueness of some entry that is used during user creation. It's useful by example to be sure that we have no conflict about email between each user. Here is how it's used (I don't understand why a path is not provided): :: # Validate uniqueness of username and mail in LDAP auth.validate_uniqueness({ 'uid': username, 'mail': mail }) And here is its docstring: .. automethod:: moulinette.authenticators.ldap.Authenticator.validate_uniqueness Get conflict ============ Like the last function `validate_uniqueness` but give instead of rising an error this function return which attribute with witch value generate a conflict. :: # Validate uniqueness of groupname in LDAP conflict = auth.get_conflict({ 'cn': groupname }, base_dn='ou=groups,dc=yunohost,dc=org') if conflict: raise YunohostError('group_name_already_exist', name=groupname) Remove entries from LDAP ======================== If you add an object linked to user, group or permission you need run the function `permission_sync_to_user` to keep integrity of permission in LDAP. Remove entries from LDAP is very simple, quite close to adding stuff except you don't need to specify the attributes dict, you just need to entrie path: :: auth.remove(path) Here how it looks like for domain and user: :: # domain auth.remove('virtualdomain=%s,ou=domains' % domain) # user auth.remove('uid=%s,ou=users' % username) :file:`auth.remove` returns something that evaluate to False when it fails (:file:`None` ?) so you need to check it returns code. .. automethod:: moulinette.authenticators.ldap.Authenticator.remove Reading LDIF file ================= Reading parsing a ldif to be able to insert in the LDAP database is really easy. Here is how to get the content of a LDIF file :: from moulinette.utils.filesystem import read_ldif my_reslut = read_ldif("your_file.ldif") Note that the main difference of what the auth object return with the search method is that this function return a 2-tuples with the "dn" and the LDAP entry. ============================= LDAP architecture in Yunohost ============================= In Yunohost to be able to manage the user and the permission we use 3 parts: * User object * Permission object * Group object We can see the interaction between these object as this following: .. image:: Yunohost_LDAP_documentation/LDAP_Liaison_logique_entre_objets.png As you can see there are link between these 3 objets: * The first link is between the user and the group. It define which user is in which group. Note that all user has a group with his name. Note that in all Yunohost instance you have a group named `all_users`. In this group you will find all Yunohost users. * The second link is between the permission and the groups. This link is defined by the administrator. By default all permission are linked to the group `all_users`, so all user will be allowed to access to this permission. * The third link between the User and the Permission is more technical. It give the possibility to the application to get a list of all user allowed to access to. This link is dynamically generated by core. The function `permission_sync_to_user` in the module `permission` do this work. The option `force` of the function `permission_sync_to_user` is used when you add the data to LDAP with `slapadd`. `slapadd` update the LDAP database without the LDAP demon process. The advantage of this is that you can bypass the integrity check (like the link between the object by the memberOf overlay). The disadvantage is that the the memberOf overlay wont update anything so if you don't fix the integrity after after to run `slapadd`, the permission in LDAP might be corrupted. Running the function permission_sync_to_user` with the option `force` will do this work to fix all integrity error. To be able to have an attribute in both is of theses 3 link we use the `memberOf` overlay in LDAP. This following line define the configuration to have these 3 link dynamically updated : :: # Link user <-> group #dn: olcOverlay={0}memberof,olcDatabase={1}mdb,cn=config overlay memberof memberof-group-oc groupOfNamesYnh memberof-member-ad member memberof-memberof-ad memberOf memberof-dangling error memberof-refint TRUE # Link permission <-> groupes #dn: olcOverlay={1}memberof,olcDatabase={1}mdb,cn=config overlay memberof memberof-group-oc permissionYnh memberof-member-ad groupPermission memberof-memberof-ad permission memberof-dangling error memberof-refint TRUE # Link permission <-> user #dn: olcOverlay={2}memberof,olcDatabase={1}mdb,cn=config overlay memberof memberof-group-oc permissionYnh memberof-member-ad inheritPermission memberof-memberof-ad permission memberof-dangling error memberof-refint TRUE This foolwing example show how will be represented in LDAP as simple concept of permission. .. image:: Yunohost_LDAP_documentation/LDAP_Representation_logique.png This schema show what will be in LDAP in these following schema: .. image:: Yunohost_LDAP_documentation/Schema_LDAP_1.png .. image:: Yunohost_LDAP_documentation/Schema_LDAP_2.png ========================================= LDAP integration in Yunohost applications ========================================= To have a complete integration of LDAP in your application you need to configure LDAP as follow : :: Host: ldap://localhost Port: 389 Base DN: dc=yunohost,dc=org User DN: ou=users,dc=yunohost,dc=org Group DN: ou=groups,dc=yunohost,dc=org fiter : (&(objectClass=posixAccount)(permission=cn=YOUR_APP.main,ou=permission,dc=yunohost,dc=org)) LDAP Username: uid LDAP Email Address: mail By this your application will get the list of all user allowed to access to your application.