.. _ldap:

=====================
Geonode auth via LDAP
=====================

Create demo LDAP
----------------

In order to test GeoNode support for LDAP authentication over the next section we'll create a simple local LDAP server.

.. code-block:: sh

  # change machine hostname
  sudo hostnamectl set-hostname ldap.example.com

  sudo vim /etc/hosts
  192.168.18.50 ldap.example.com

  sudo apt -y install slapd ldap-utils

  # NOTE: You will be prompted to provide slapd an admin account password

  # check if slapd install is ok

  sudo slapcat

  # You should receive a similar content response

  > dn: dc=example,dc=com
    objectClass: top
    objectClass: dcObject
    objectClass: organization
    o: example.com
    dc: example
    structuralObjectClass: organization
    entryUUID: c183e400-c205-103b-9ba4-0b759e265ed4
    creatorsName: cn=admin,dc=example,dc=com
    createTimestamp: 20211015131547Z
    entryCSN: 20211015131547.819933Z#000000#000#000000
    modifiersName: cn=admin,dc=example,dc=com
    modifyTimestamp: 20211015131547Z

    dn: cn=admin,dc=example,dc=com
    objectClass: simpleSecurityObject
    objectClass: organizationalRole
    cn: admin
    description: LDAP administrator
    userPassword:: e1NTSEF9RlBEQmdmcEJiL2ZnQkUzeGJRb2hObG5GczdmN0VIQmY=
    structuralObjectClass: organizationalRole
    entryUUID: c186ea1a-c205-103b-9ba5-0b759e265ed4
    creatorsName: cn=admin,dc=example,dc=com
    createTimestamp: 20211015131547Z
    entryCSN: 20211015131547.839808Z#000000#000#000000
    modifiersName: cn=admin,dc=example,dc=com
    modifyTimestamp: 20211015131547Z

    # Create base geonode users ldap file
    mkdir -p /opt/geonode/ldap
    cd /opt/geonode/ldap
    vim geonodedn.ldif

    # Create the following content and save file after
    dn: ou=users,dc=example,dc=com
    objectClass: organizationalUnit
    ou: users

    dn: ou=groups,dc=example,dc=com
    objectClass: organizationalUnit
    ou: groups

    # add an admin user to our ldap (use the ldap password on install step)
    sudo ldapadd -x -D cn=admin,dc=example,dc=com -W -f geonodedn.ldif

    # generate a password for the user account to add
    slappasswd
    New password:
    Re-enter new password:
    {SSHA}u0Qj+PWagxB5sV7z0X0MQLXleLARzo8k

    # create a ldif file for geonode users
    vim ldapusers.ldif

    # add a similar content
    # replace <my-user> with your username
    dn: uid=<my-user>,ou=users,dc=example,dc=com
    objectClass: inetOrgPerson
    objectClass: posixAccount
    objectClass: shadowAccount
    cn: geonode
    sn: Wiz
    userPassword: {SSHA}u0Qj+PWagxB5sV7z0X0MQLXleLARzo8k
    loginShell: /bin/bash
    uidNumber: 2000
    gidNumber: 2000
    homeDirectory: /home/<my-user>

    # create the ldap user
    sudo ldapadd -x -D cn=admin,dc=example,dc=com -W -f ldapusers.ldif

    # create a ldap group
    vim ldapgroups.ldif

    # add the following content
    dn: cn=geonode,ou=groups,dc=example,dc=com
    objectClass: posixGroup
    cn: geonode
    gidNumber: 2000
    memberUid: geonode

    # create the geonode ldap group
    ldapadd -x -D cn=admin,dc=example,dc=com -W -f ldapgroups.ldif


This package provides utilities for using LDAP as an authentication and
authorization backend for geonode.

The `django_auth_ldap <https://django-auth-ldap.readthedocs.io/en/latest/>`_ package is a very capable way to add LDAP integration
with django projects. It provides a lot of flexibility in mapping LDAP users to
geonode users and is able to manage user authentication.

However, in order to provide full support for mapping LDAP groups with
geonode's and enforce group permissions on resources, a custom geonode
authentication backend  is required. This contrib package provides such a
backend, based on `django_auth_ldap <https://django-auth-ldap.readthedocs.io/en/latest/>`_.


Installation
------------

Installing this contrib package is a matter of:

1. Installing system LDAP libraries (development packages needed)
2. Cloning this repository locally
3. Change to the `ldap` directory and install this contrib package

  .. code-block:: sh

    # install systemwide LDAP libraries
    sudo apt install libldap2-dev libsasl2-dev

    # get geonode/contribs code
    cd /opt
    git clone https://github.com/GeoNode/geonode-contribs.git

    # optional: if deactivate our virtualenv activate it again
    workon geonode

    # install geonode ldap contrib package
    cd geonode-contribs/ldap
    pip install .

Configuration
-------------

1. Add ``geonode_ldap.backend.GeonodeLdapBackend`` as an additional auth
   backend.

  .. code-block:: python

        # e.g. by updating your settings.py or local_settings.py
        AUTHENTICATION_BACKENDS += (
            "geonode_ldap.backend.GeonodeLdapBackend",
        )

   # open setting.py or local_settings.py and locate AUTHENTICATION_BACKENDS
   # add the new backend line as above

  .. code-block:: shell

    cd /opt/geonode/geonode
    vim settings.py


   You may use additional auth backends, the django authentication framework
   tries them all according to the order listed in the settings. This means that
   geonode can be setup in such a way as to permit internal organization users
   to login with their LDAP credentials, while at the same time allowing for
   casual users to use their facebook login (as long as you enable facebook
   social auth provider).

   .. note:: The django's ``django.contrib.auth.backends.ModelBackend`` must also be used in order to provide full geonode integration with LDAP.
        However this is included by default on GeoNode ``settings``

        .. code-block:: python

            # The GeoNode default settings are the following
            AUTHENTICATION_BACKENDS = (
                'oauth2_provider.backends.OAuth2Backend',
                'django.contrib.auth.backends.ModelBackend',
                'guardian.backends.ObjectPermissionBackend',
                'allauth.account.auth_backends.AuthenticationBackend',
            )

2. Set some additional configuration values. Some of these variables are
   prefixed with ``AUTH_LDAP`` (these are used directly by `django_auth_ldap <https://django-auth-ldap.readthedocs.io/en/latest/>`_)
   while others are prefixed with ``GEONODE_LDAP`` (these are used by
   ``geonode_ldap``). The geonode custom variables are:

   * ``GEONODE_LDAP_GROUP_PROFILE_FILTERSTR`` - This is an LDAP search fragment
     with the filter that allows querying for existing groups. See example below

   * ``GEONODE_LDAP_GROUP_NAME_ATTRIBUTE`` - This is the name of the LDAP
     attribute that will be used for deriving the geonode group name. If not
     specified it will default to `cn`, which means that the LDAP object's
     `common name` will be used for generating the name of the geonode group

   * ``GEONODE_LDAP_GROUP_PROFILE_MEMBER_ATTR`` - This is the name of the LDAP
     attribute that will be used for deriving the geonode membership. If not
     specified it will default to ``member``


Example configuration:

.. code-block:: python

    # add these import lines to the top of your geonode settings file
    from django_auth_ldap import config as ldap_config
    from geonode_ldap.config import GeonodeNestedGroupOfNamesType
    import ldap

    # enable logging
    import logging
    logger = logging.getLogger('django_auth_ldap')
    logger.addHandler(logging.StreamHandler())
    logger.setLevel(logging.DEBUG)

    # add both standard ModelBackend auth and geonode.contrib.ldap auth
    AUTHENTICATION_BACKENDS += (
        'geonode_ldap.backend.GeonodeLdapBackend',
    )

    # django_auth_ldap configuration
    AUTH_LDAP_SERVER_URI = os.getenv("LDAP_SERVER_URL")
    AUTH_LDAP_BIND_DN = os.getenv("LDAP_BIND_DN")
    AUTH_LDAP_BIND_PASSWORD = os.getenv("LDAP_BIND_PASSWORD")
    AUTH_LDAP_USER_SEARCH = ldap_config.LDAPSearch(
        os.getenv("LDAP_USER_SEARCH_DN"),
        ldap.SCOPE_SUBTREE,
        os.getenv("LDAP_USER_SEARCH_FILTERSTR")
    )
    # should LDAP groups be used to spawn groups in GeoNode?
    AUTH_LDAP_MIRROR_GROUPS = strtobool(os.getenv("LDAP_MIRROR_GROUPS", 'True'))
    AUTH_LDAP_GROUP_SEARCH = ldap_config.LDAPSearch(
        os.getenv("LDAP_GROUP_SEARCH_DN"),
        ldap.SCOPE_SUBTREE,
        os.getenv("LDAP_GROUP_SEARCH_FILTERSTR")
    )
    AUTH_LDAP_GROUP_TYPE = GeonodeNestedGroupOfNamesType()
    AUTH_LDAP_USER_ATTR_MAP = {
        "first_name": "givenName",
        "last_name": "sn",
        "email": "mailPrimaryAddress"
    }
    AUTH_LDAP_FIND_GROUP_PERMS = True
    AUTH_LDAP_MIRROR_GROUPS_EXCEPT = [
        "test_group"
    ]

    # these are not needed by django_auth_ldap - we use them to find and match
    # GroupProfiles and GroupCategories
    GEONODE_LDAP_GROUP_NAME_ATTRIBUTE = os.getenv("LDAP_GROUP_NAME_ATTRIBUTE", default="cn")
    GEONODE_LDAP_GROUP_PROFILE_FILTERSTR = os.getenv("LDAP_GROUP_SEARCH_FILTERSTR", default='(ou=research group)')
    GEONODE_LDAP_GROUP_PROFILE_MEMBER_ATTR = os.getenv("LDAP_GROUP_PROFILE_MEMBER_ATTR", default='member')

Example environment variables: (add these to the previous geonode.ini file created under wgsi installation)

.. code-block:: shell

    LDAP_SERVER_URL=ldap://<the_ldap_server>
    LDAP_BIND_DN=uid=ldapinfo,cn=users,dc=ad,dc=example,dc=org
    LDAP_BIND_PASSWORD=<something_secret>
    LDAP_USER_SEARCH_DN=dc=ad,dc=example,dc=org
    LDAP_USER_SEARCH_FILTERSTR=(&(uid=%(user)s)(objectClass=person))
    LDAP_MIRROR_GROUPS=True
    LDAP_GROUP_SEARCH_DN=cn=groups,dc=ad,dc=example,dc=org
    LDAP_GROUP_SEARCH_FILTERSTR=(|(cn=abt1)(cn=abt2)(cn=abt3)(cn=abt4)(cn=abt5)(cn=abt6))
    LDAP_GROUP_PROFILE_MEMBER_ATTR=uniqueMember

The configuration seen in the example above will allow LDAP users to login to
geonode with their LDAP credentials.

On first login, a geonode user is created from the LDAP user and its LDAP
attributes ``cn`` and ``sn`` are used to populate the geonode user's
``first_name`` and ``last_name`` profile fields.

Any groups that the user is a member of in LDAP (under the
``cn=groups,dc=ad,dc=example,dc=org`` search base and belonging to one of
``(|(cn=abt1)(cn=abt2)(cn=abt3)(cn=abt4)(cn=abt5)(cn=abt6))`` groups) will be mapped to the corresponding
geonode groups, even creating these groups in geonode in case they do not
exist yet. The geonode user is also made a member of these geonode groups.

Upon each login, the user's geonode group memberships are re-evaluated
according to the information extracted from LDAP. The
``AUTH_LDAP_MIRROR_GROUPS_EXCEPT`` setting can be used to specify groups
whose memberships will not be re-evaluated.

If no LDAP groups shall be mirrored ``LDAP_MIRROR_GROUPS`` and ``LDAP_MIRROR_GROUPS_EXCEPT`` must be set to ``False``.

.. note:: Users mapped from LDAP will be marked with an ``ldap`` tag. This will be used to keep them in sync.

.. warning:: If you remove the ``ldap`` tag, the users will be threaten as pure internal GeoNode ones.

You may also manually generate the geonode groups in advance, before users
login. In this case, when a user logs in and the mapped LDAP group already
exists, the user is merely added to the geonode group

Be sure to check out `django_auth_ldap <https://django-auth-ldap.readthedocs.io/en/latest/>`_ for more information on the various
configuration options.

Keep Users and Groups Synchronized
----------------------------------

In order to constantly keep the remote LDAP Users and Groups **synchronized** with GeoNode,
you will need to run periodically some specific management commands.

.. code-block:: shell

    */10 * * * * /opt/geonode/my-geonode/manage.sh updateldapgroups  >> /var/log/cron.log 2>&1
    */10 * * * * /opt/geonode/my-geonode/manage.sh updateldapusers   >> /var/log/cron.log 2>&1

Where the ``manage.sh`` is a bash script similar to the following one:

**manage.sh**

.. code-block:: shell

    export $(grep -v '^#' /opt/geonode/my-geonode/.env | xargs -d '\n'); /home/<my_user>/.virtualenvs/geonode/bin/python /opt/geonode/my-geonode/manage.py $@

and the ``/opt/geonode/my-geonode/.env`` is something similar to the following one:

**/opt/geonode/my-geonode/.env**

.. code-block:: shell

    DEBUG=False
    DJANGO_ALLOWED_HOSTS=<geonode_public_host>,localhost,127.0.0.1
    DJANGO_DATABASE_URL=postgis://my_geonode:**********@localhost:5432/my_geonode_db
    DEFAULT_BACKEND_UPLOADER=geonode.importer
    DEFAULT_FROM_EMAIL=geonode@example.org
    DJANGO_EMAIL_HOST=smtp.example.org
    DJANGO_EMAIL_HOST_PASSWORD=**********
    DJANGO_EMAIL_HOST_USER=geonode
    DJANGO_EMAIL_PORT=465
    DJANGO_EMAIL_USE_SSL=True
    DJANGO_SETTINGS_MODULE=my_geonode.settings
    DJANGO_SECRET_KEY=**********
    OAUTH2_API_KEY=**********
    PROXY_URL=/proxy/?url=
    EXIF_ENABLED=True
    EMAIL_ENABLE=True
    TIME_ENABLED=True
    ACCOUNT_OPEN_SIGNUP=True
    ACCOUNT_APPROVAL_REQUIRED=True
    ACCOUNT_EMAIL_REQUIRED=True
    ACCOUNT_EMAIL_VERIFICATION=optional
    AVATAR_GRAVATAR_SSL=True
    GEONODE_DB_URL=postgis://my_geonode:**********@localhost:5432/my_geonode_data
    GEOSERVER_ADMIN_PASSWORD=**********
    GEOSERVER_LOCATION=https://<geonode_public_host>/geoserver/
    GEOSERVER_PUBLIC_HOST=<geonode_public_host>
    GEOSERVER_PUBLIC_LOCATION=https://<geonode_public_host>/geoserver/
    GEOSERVER_WEB_UI_LOCATION=https://<geonode_public_host>/geoserver/
    LDAP_SERVER_URL=ldap://<the_ldap_server>
    LDAP_BIND_DN=uid=ldapinfo,cn=users,dc=ad,dc=example,dc=org
    LDAP_BIND_PASSWORD=<something_secret>
    LDAP_USER_SEARCH_DN=dc=ad,dc=example,dc=org
    LDAP_USER_SEARCH_FILTERSTR=(&(uid=%(user)s)(objectClass=person))
    LDAP_MIRROR_GROUPS=True
    LDAP_GROUP_SEARCH_DN=cn=groups,dc=ad,dc=example,dc=org
    LDAP_GROUP_SEARCH_FILTERSTR=(|(cn=abt1)(cn=abt2)(cn=abt3)(cn=abt4)(cn=abt5)(cn=abt6))
    LDAP_GROUP_PROFILE_MEMBER_ATTR=uniqueMember
    OGC_REQUEST_MAX_RETRIES=3
    OGC_REQUEST_POOL_CONNECTIONS=100
    OGC_REQUEST_POOL_MAXSIZE=100
    OGC_REQUEST_TIMEOUT=60
    SITEURL=https://<geonode_public_host>/
    SITE_HOST_NAME=<geonode_public_host>
    FREETEXT_KEYWORDS_READONLY=False
    # Advanced Workflow Settings
    ADMIN_MODERATE_UPLOADS=False
    GROUP_MANDATORY_RESOURCES=False
    GROUP_PRIVATE_RESOURCES=False
    RESOURCE_PUBLISHING=False

.. note:: You might want to use the same ``/opt/geonode/my-geonode/.env`` for your ``UWSGI`` configuration too:

    .. code-block:: shell

        [uwsgi]
        socket = 0.0.0.0:8000
        uid = <my_user>
        gid = www-data

        plugins = python3
        virtualenv = /home/<my_user>/.virtualenvs/geonode

        # set environment variables from .env file
        env LANG=en_US.utf8
        env LC_ALL=en_US.UTF-8
        env LC_LANG=en_US.UTF-8

        for-readline = /opt/geonode/my-geonode/.env
            env = %(_)
        endfor =

        chdir = /opt/geonode/my-geonode
        module = my_geonode.wsgi:application

        processes = 12
        threads = 2
        enable-threads = true
        master = true

        # logging
        # path to where uwsgi logs will be saved
        logto = /storage/my_geonode/logs/geonode.log
        daemonize = /storage/my_geonode/logs/geonode.log
        touch-reload = /opt/geonode/my-geonode/my_geonode/wsgi.py
        buffer-size = 32768
        max-requests = 500
        harakiri = 300 # respawn processes taking more than 5 minutes (300 seconds)
        # limit-as = 1024 # avoid Errno 12 cannot allocate memory
        harakiri-verbose = true
        vacuum = true
        thunder-lock = true