sources/ldap: add forward deletion option (#14718)

* sources/ldap: add forward deletion option

* remove unnecessary `blank=True`

* clarify `validated_by` `help_text`

* add indices to `validated_by`

* factor out `get_identifier` everywhere and `get_attributes`

I don't know what that additional `in` check is for, but I'm not about
to find out.

* add tests for known good user and group

* fixup! add tests for known good user and group

* fixup! add tests for known good user and group

authentik/sources/ldap/api.py

@@ -111,6 +111,7 @@ class LDAPSourceSerializer(SourceSerializer):
             "sync_parent_group",
             "connectivity",
             "lookup_groups_from_user",
+            "delete_not_found_objects",
         ]
         extra_kwargs = {"bind_password": {"write_only": True}}
 
@@ -147,6 +148,7 @@ class LDAPSourceViewSet(UsedByMixin, ModelViewSet):
         "user_property_mappings",
         "group_property_mappings",
         "lookup_groups_from_user",
+        "delete_not_found_objects",
     ]
     search_fields = ["name", "slug"]
     ordering = ["name"]

authentik/sources/ldap/migrations/0009_groupldapsourceconnection_validated_by_and_more.py

@@ -0,0 +1,48 @@
+# Generated by Django 5.1.9 on 2025-05-28 08:15
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("authentik_core", "0048_delete_oldauthenticatedsession_content_type"),
+        ("authentik_sources_ldap", "0008_groupldapsourceconnection_userldapsourceconnection"),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name="groupldapsourceconnection",
+            name="validated_by",
+            field=models.UUIDField(
+                blank=True,
+                help_text="Unique ID used while checking if this object still exists in the directory.",
+                null=True,
+            ),
+        ),
+        migrations.AddField(
+            model_name="ldapsource",
+            name="delete_not_found_objects",
+            field=models.BooleanField(
+                default=False,
+                help_text="Delete authentik users and groups which were previously supplied by this source, but are now missing from it.",
+            ),
+        ),
+        migrations.AddField(
+            model_name="userldapsourceconnection",
+            name="validated_by",
+            field=models.UUIDField(
+                blank=True,
+                help_text="Unique ID used while checking if this object still exists in the directory.",
+                null=True,
+            ),
+        ),
+        migrations.AddIndex(
+            model_name="groupldapsourceconnection",
+            index=models.Index(fields=["validated_by"], name="authentik_s_validat_b70447_idx"),
+        ),
+        migrations.AddIndex(
+            model_name="userldapsourceconnection",
+            index=models.Index(fields=["validated_by"], name="authentik_s_validat_ff2ebc_idx"),
+        ),
+    ]

authentik/sources/ldap/models.py

@@ -137,6 +137,14 @@ class LDAPSource(Source):
         ),
     )
 
+    delete_not_found_objects = models.BooleanField(
+        default=False,
+        help_text=_(
+            "Delete authentik users and groups which were previously supplied by this source, "
+            "but are now missing from it."
+        ),
+    )
+
     @property
     def component(self) -> str:
         return "ak-source-ldap-form"
@@ -321,6 +329,12 @@ class LDAPSourcePropertyMapping(PropertyMapping):
 
 
 class UserLDAPSourceConnection(UserSourceConnection):
+    validated_by = models.UUIDField(
+        null=True,
+        blank=True,
+        help_text=_("Unique ID used while checking if this object still exists in the directory."),
+    )
+
     @property
     def serializer(self) -> type[Serializer]:
         from authentik.sources.ldap.api import (
@@ -332,9 +346,18 @@ class UserLDAPSourceConnection(UserSourceConnection):
     class Meta:
         verbose_name = _("User LDAP Source Connection")
         verbose_name_plural = _("User LDAP Source Connections")
+        indexes = [
+            models.Index(fields=["validated_by"]),
+        ]
 
 
 class GroupLDAPSourceConnection(GroupSourceConnection):
+    validated_by = models.UUIDField(
+        null=True,
+        blank=True,
+        help_text=_("Unique ID used while checking if this object still exists in the directory."),
+    )
+
     @property
     def serializer(self) -> type[Serializer]:
         from authentik.sources.ldap.api import (
@@ -346,3 +369,6 @@ class GroupLDAPSourceConnection(GroupSourceConnection):
     class Meta:
         verbose_name = _("Group LDAP Source Connection")
         verbose_name_plural = _("Group LDAP Source Connections")
+        indexes = [
+            models.Index(fields=["validated_by"]),
+        ]

authentik/sources/ldap/sync/base.py

@@ -9,7 +9,7 @@ from structlog.stdlib import BoundLogger, get_logger
 from authentik.core.sources.mapper import SourceMapper
 from authentik.lib.config import CONFIG
 from authentik.lib.sync.mapper import PropertyMappingManager
-from authentik.sources.ldap.models import LDAPSource
+from authentik.sources.ldap.models import LDAPSource, flatten
 
 
 class BaseLDAPSynchronizer:
@@ -77,6 +77,16 @@ class BaseLDAPSynchronizer:
         """Get objects from LDAP, implemented in subclass"""
         raise NotImplementedError()
 
+    def get_attributes(self, object):
+        if "attributes" not in object:
+            return
+        return object.get("attributes", {})
+
+    def get_identifier(self, attributes: dict):
+        if not attributes.get(self._source.object_uniqueness_field):
+            return
+        return flatten(attributes[self._source.object_uniqueness_field])
+
     def search_paginator(  # noqa: PLR0913
         self,
         search_base,

authentik/sources/ldap/sync/forward_delete_groups.py

@@ -0,0 +1,61 @@
+from collections.abc import Generator
+from itertools import batched
+from uuid import uuid4
+
+from ldap3 import SUBTREE
+
+from authentik.core.models import Group
+from authentik.sources.ldap.models import GroupLDAPSourceConnection
+from authentik.sources.ldap.sync.base import BaseLDAPSynchronizer
+from authentik.sources.ldap.sync.forward_delete_users import DELETE_CHUNK_SIZE, UPDATE_CHUNK_SIZE
+
+
+class GroupLDAPForwardDeletion(BaseLDAPSynchronizer):
+    """Delete LDAP Groups from authentik"""
+
+    @staticmethod
+    def name() -> str:
+        return "group_deletions"
+
+    def get_objects(self, **kwargs) -> Generator:
+        if not self._source.sync_groups or not self._source.delete_not_found_objects:
+            self.message("Group syncing is disabled for this Source")
+            return iter(())
+
+        uuid = uuid4()
+        groups = self._source.connection().extend.standard.paged_search(
+            search_base=self.base_dn_groups,
+            search_filter=self._source.group_object_filter,
+            search_scope=SUBTREE,
+            attributes=[self._source.object_uniqueness_field],
+            generator=True,
+            **kwargs,
+        )
+        for batch in batched(groups, UPDATE_CHUNK_SIZE, strict=False):
+            identifiers = []
+            for group in batch:
+                if not (attributes := self.get_attributes(group)):
+                    continue
+                if identifier := self.get_identifier(attributes):
+                    identifiers.append(identifier)
+            GroupLDAPSourceConnection.objects.filter(identifier__in=identifiers).update(
+                validated_by=uuid
+            )
+
+        return batched(
+            GroupLDAPSourceConnection.objects.filter(source=self._source)
+            .exclude(validated_by=uuid)
+            .values_list("group", flat=True)
+            .iterator(chunk_size=DELETE_CHUNK_SIZE),
+            DELETE_CHUNK_SIZE,
+            strict=False,
+        )
+
+    def sync(self, group_pks: tuple) -> int:
+        """Delete authentik groups"""
+        if not self._source.sync_groups or not self._source.delete_not_found_objects:
+            self.message("Group syncing is disabled for this Source")
+            return -1
+        self._logger.debug("Deleting groups", group_pks=group_pks)
+        _, deleted_per_type = Group.objects.filter(pk__in=group_pks).delete()
+        return deleted_per_type.get(Group._meta.label, 0)

authentik/sources/ldap/sync/forward_delete_users.py

@@ -0,0 +1,63 @@
+from collections.abc import Generator
+from itertools import batched
+from uuid import uuid4
+
+from ldap3 import SUBTREE
+
+from authentik.core.models import User
+from authentik.sources.ldap.models import UserLDAPSourceConnection
+from authentik.sources.ldap.sync.base import BaseLDAPSynchronizer
+
+UPDATE_CHUNK_SIZE = 10_000
+DELETE_CHUNK_SIZE = 50
+
+
+class UserLDAPForwardDeletion(BaseLDAPSynchronizer):
+    """Delete LDAP Users from authentik"""
+
+    @staticmethod
+    def name() -> str:
+        return "user_deletions"
+
+    def get_objects(self, **kwargs) -> Generator:
+        if not self._source.sync_users or not self._source.delete_not_found_objects:
+            self.message("User syncing is disabled for this Source")
+            return iter(())
+
+        uuid = uuid4()
+        users = self._source.connection().extend.standard.paged_search(
+            search_base=self.base_dn_users,
+            search_filter=self._source.user_object_filter,
+            search_scope=SUBTREE,
+            attributes=[self._source.object_uniqueness_field],
+            generator=True,
+            **kwargs,
+        )
+        for batch in batched(users, UPDATE_CHUNK_SIZE, strict=False):
+            identifiers = []
+            for user in batch:
+                if not (attributes := self.get_attributes(user)):
+                    continue
+                if identifier := self.get_identifier(attributes):
+                    identifiers.append(identifier)
+            UserLDAPSourceConnection.objects.filter(identifier__in=identifiers).update(
+                validated_by=uuid
+            )
+
+        return batched(
+            UserLDAPSourceConnection.objects.filter(source=self._source)
+            .exclude(validated_by=uuid)
+            .values_list("user", flat=True)
+            .iterator(chunk_size=DELETE_CHUNK_SIZE),
+            DELETE_CHUNK_SIZE,
+            strict=False,
+        )
+
+    def sync(self, user_pks: tuple) -> int:
+        """Delete authentik users"""
+        if not self._source.sync_users or not self._source.delete_not_found_objects:
+            self.message("User syncing is disabled for this Source")
+            return -1
+        self._logger.debug("Deleting users", user_pks=user_pks)
+        _, deleted_per_type = User.objects.filter(pk__in=user_pks).delete()
+        return deleted_per_type.get(User._meta.label, 0)

authentik/sources/ldap/sync/groups.py

@@ -58,18 +58,16 @@ class GroupLDAPSynchronizer(BaseLDAPSynchronizer):
             return -1
         group_count = 0
         for group in page_data:
-            if "attributes" not in group:
+            if (attributes := self.get_attributes(group)) is None:
                 continue
-            attributes = group.get("attributes", {})
             group_dn = flatten(flatten(group.get("entryDN", group.get("dn"))))
-            if not attributes.get(self._source.object_uniqueness_field):
+            if not (uniq := self.get_identifier(attributes)):
                 self.message(
                     f"Uniqueness field not found/not set in attributes: '{group_dn}'",
                     attributes=attributes.keys(),
                     dn=group_dn,
                 )
                 continue
-            uniq = flatten(attributes[self._source.object_uniqueness_field])
             try:
                 defaults = {
                     k: flatten(v)

authentik/sources/ldap/sync/membership.py

@@ -63,9 +63,9 @@ class MembershipLDAPSynchronizer(BaseLDAPSynchronizer):
                     group_member_dn = group_member.get("dn", {})
                     members.append(group_member_dn)
             else:
-                if "attributes" not in group:
+                if (attributes := self.get_attributes(group)) is None:
                     continue
-                members = group.get("attributes", {}).get(self._source.group_membership_field, [])
+                members = attributes.get(self._source.group_membership_field, [])
 
             ak_group = self.get_group(group)
             if not ak_group:

authentik/sources/ldap/sync/users.py

@@ -60,18 +60,16 @@ class UserLDAPSynchronizer(BaseLDAPSynchronizer):
             return -1
         user_count = 0
         for user in page_data:
-            if "attributes" not in user:
+            if (attributes := self.get_attributes(user)) is None:
                 continue
-            attributes = user.get("attributes", {})
             user_dn = flatten(user.get("entryDN", user.get("dn")))
-            if not attributes.get(self._source.object_uniqueness_field):
+            if not (uniq := self.get_identifier(attributes)):
                 self.message(
                     f"Uniqueness field not found/not set in attributes: '{user_dn}'",
                     attributes=attributes.keys(),
                     dn=user_dn,
                 )
                 continue
-            uniq = flatten(attributes[self._source.object_uniqueness_field])
             try:
                 defaults = {
                     k: flatten(v)

authentik/sources/ldap/tasks.py

@@ -17,6 +17,8 @@ from authentik.lib.utils.reflection import class_to_path, path_to_class
 from authentik.root.celery import CELERY_APP
 from authentik.sources.ldap.models import LDAPSource
 from authentik.sources.ldap.sync.base import BaseLDAPSynchronizer
+from authentik.sources.ldap.sync.forward_delete_groups import GroupLDAPForwardDeletion
+from authentik.sources.ldap.sync.forward_delete_users import UserLDAPForwardDeletion
 from authentik.sources.ldap.sync.groups import GroupLDAPSynchronizer
 from authentik.sources.ldap.sync.membership import MembershipLDAPSynchronizer
 from authentik.sources.ldap.sync.users import UserLDAPSynchronizer
@@ -52,11 +54,11 @@ def ldap_connectivity_check(pk: str | None = None):
 
 
 @CELERY_APP.task(
-    # We take the configured hours timeout time by 2.5 as we run user and
+    # We take the configured hours timeout time by 3.5 as we run user and
-    # group in parallel and then membership, so 2x is to cover the serial tasks,
+    # group in parallel and then membership, then deletions, so 3x is to cover the serial tasks,
     # and 0.5x on top of that to give some more leeway
-    soft_time_limit=(60 * 60 * CONFIG.get_int("ldap.task_timeout_hours")) * 2.5,
+    soft_time_limit=(60 * 60 * CONFIG.get_int("ldap.task_timeout_hours")) * 3.5,
-    task_time_limit=(60 * 60 * CONFIG.get_int("ldap.task_timeout_hours")) * 2.5,
+    task_time_limit=(60 * 60 * CONFIG.get_int("ldap.task_timeout_hours")) * 3.5,
 )
 def ldap_sync_single(source_pk: str):
     """Sync a single source"""
@@ -79,6 +81,25 @@ def ldap_sync_single(source_pk: str):
             group(
                 ldap_sync_paginator(source, MembershipLDAPSynchronizer),
             ),
+            # Finally, deletions. What we'd really like to do here is something like
+            # ```
+            # user_identifiers = <ldap query>
+            # User.objects.exclude(
+            #     usersourceconnection__identifier__in=user_uniqueness_identifiers,
+            # ).delete()
+            # ```
+            # This runs into performance issues in large installations. So instead we spread the
+            # work out into three steps:
+            # 1. Get every object from the LDAP source.
+            # 2. Mark every object as "safe" in the database. This is quick, but any error could
+            #    mean deleting users which should not be deleted, so we do it immediately, in
+            #    large chunks, and only queue the deletion step afterwards.
+            # 3. Delete every unmarked item. This is slow, so we spread it over many tasks in
+            #    small chunks.
+            group(
+                ldap_sync_paginator(source, UserLDAPForwardDeletion)
+                + ldap_sync_paginator(source, GroupLDAPForwardDeletion),
+            ),
         )
         task()
 

authentik/sources/ldap/tests/mock_slapd.py

@@ -2,6 +2,33 @@
 
 from ldap3 import MOCK_SYNC, OFFLINE_SLAPD_2_4, Connection, Server
 
+# The mock modifies these in place, so we have to define them per string
+user_in_slapd_dn = "cn=user_in_slapd_cn,ou=users,dc=goauthentik,dc=io"
+user_in_slapd_cn = "user_in_slapd_cn"
+user_in_slapd_uid = "user_in_slapd_uid"
+user_in_slapd_object_class = "person"
+user_in_slapd = {
+    "dn": user_in_slapd_dn,
+    "attributes": {
+        "cn": user_in_slapd_cn,
+        "uid": user_in_slapd_uid,
+        "objectClass": user_in_slapd_object_class,
+    },
+}
+group_in_slapd_dn = "cn=user_in_slapd_cn,ou=groups,dc=goauthentik,dc=io"
+group_in_slapd_cn = "group_in_slapd_cn"
+group_in_slapd_uid = "group_in_slapd_uid"
+group_in_slapd_object_class = "groupOfNames"
+group_in_slapd = {
+    "dn": group_in_slapd_dn,
+    "attributes": {
+        "cn": group_in_slapd_cn,
+        "uid": group_in_slapd_uid,
+        "objectClass": group_in_slapd_object_class,
+        "member": [user_in_slapd["dn"]],
+    },
+}
+
 
 def mock_slapd_connection(password: str) -> Connection:
     """Create mock SLAPD connection"""
@@ -96,5 +123,14 @@ def mock_slapd_connection(password: str) -> Connection:
             "objectClass": "posixAccount",
         },
     )
+    # Known user and group
+    connection.strategy.add_entry(
+        user_in_slapd["dn"],
+        user_in_slapd["attributes"],
+    )
+    connection.strategy.add_entry(
+        group_in_slapd["dn"],
+        group_in_slapd["attributes"],
+    )
     connection.bind()
     return connection

authentik/sources/ldap/tests/test_sync.py

@@ -13,14 +13,26 @@ from authentik.events.system_tasks import TaskStatus
 from authentik.lib.generators import generate_id, generate_key
 from authentik.lib.sync.outgoing.exceptions import StopSync
 from authentik.lib.utils.reflection import class_to_path
-from authentik.sources.ldap.models import LDAPSource, LDAPSourcePropertyMapping
+from authentik.sources.ldap.models import (
+    GroupLDAPSourceConnection,
+    LDAPSource,
+    LDAPSourcePropertyMapping,
+    UserLDAPSourceConnection,
+)
+from authentik.sources.ldap.sync.forward_delete_users import DELETE_CHUNK_SIZE
 from authentik.sources.ldap.sync.groups import GroupLDAPSynchronizer
 from authentik.sources.ldap.sync.membership import MembershipLDAPSynchronizer
 from authentik.sources.ldap.sync.users import UserLDAPSynchronizer
 from authentik.sources.ldap.tasks import ldap_sync, ldap_sync_all
 from authentik.sources.ldap.tests.mock_ad import mock_ad_connection
 from authentik.sources.ldap.tests.mock_freeipa import mock_freeipa_connection
-from authentik.sources.ldap.tests.mock_slapd import mock_slapd_connection
+from authentik.sources.ldap.tests.mock_slapd import (
+    group_in_slapd_cn,
+    group_in_slapd_uid,
+    mock_slapd_connection,
+    user_in_slapd_cn,
+    user_in_slapd_uid,
+)
 
 LDAP_PASSWORD = generate_key()
 
@@ -308,3 +320,160 @@ class LDAPSyncTests(TestCase):
         connection = MagicMock(return_value=mock_slapd_connection(LDAP_PASSWORD))
         with patch("authentik.sources.ldap.models.LDAPSource.connection", connection):
             ldap_sync_all.delay().get()
+
+    def test_user_deletion(self):
+        """Test user deletion"""
+        user = User.objects.create_user(username="not-in-the-source")
+        UserLDAPSourceConnection.objects.create(
+            user=user, source=self.source, identifier="not-in-the-source"
+        )
+        self.source.object_uniqueness_field = "uid"
+        self.source.group_object_filter = "(objectClass=groupOfNames)"
+        self.source.delete_not_found_objects = True
+        self.source.save()
+
+        connection = MagicMock(return_value=mock_slapd_connection(LDAP_PASSWORD))
+        with patch("authentik.sources.ldap.models.LDAPSource.connection", connection):
+            ldap_sync_all.delay().get()
+        self.assertFalse(User.objects.filter(username="not-in-the-source").exists())
+
+    def test_user_deletion_still_in_source(self):
+        """Test that user is not deleted if it's still in the source"""
+        username = user_in_slapd_cn
+        identifier = user_in_slapd_uid
+        user = User.objects.create_user(username=username)
+        UserLDAPSourceConnection.objects.create(
+            user=user, source=self.source, identifier=identifier
+        )
+        self.source.object_uniqueness_field = "uid"
+        self.source.group_object_filter = "(objectClass=groupOfNames)"
+        self.source.delete_not_found_objects = True
+        self.source.save()
+
+        connection = MagicMock(return_value=mock_slapd_connection(LDAP_PASSWORD))
+        with patch("authentik.sources.ldap.models.LDAPSource.connection", connection):
+            ldap_sync_all.delay().get()
+        self.assertTrue(User.objects.filter(username=username).exists())
+
+    def test_user_deletion_no_sync(self):
+        """Test that user is not deleted if sync_users is False"""
+        user = User.objects.create_user(username="not-in-the-source")
+        UserLDAPSourceConnection.objects.create(
+            user=user, source=self.source, identifier="not-in-the-source"
+        )
+        self.source.object_uniqueness_field = "uid"
+        self.source.group_object_filter = "(objectClass=groupOfNames)"
+        self.source.delete_not_found_objects = True
+        self.source.sync_users = False
+        self.source.save()
+
+        connection = MagicMock(return_value=mock_slapd_connection(LDAP_PASSWORD))
+        with patch("authentik.sources.ldap.models.LDAPSource.connection", connection):
+            ldap_sync_all.delay().get()
+        self.assertTrue(User.objects.filter(username="not-in-the-source").exists())
+
+    def test_user_deletion_no_delete(self):
+        """Test that user is not deleted if delete_not_found_objects is False"""
+        user = User.objects.create_user(username="not-in-the-source")
+        UserLDAPSourceConnection.objects.create(
+            user=user, source=self.source, identifier="not-in-the-source"
+        )
+        self.source.object_uniqueness_field = "uid"
+        self.source.group_object_filter = "(objectClass=groupOfNames)"
+        self.source.save()
+
+        connection = MagicMock(return_value=mock_slapd_connection(LDAP_PASSWORD))
+        with patch("authentik.sources.ldap.models.LDAPSource.connection", connection):
+            ldap_sync_all.delay().get()
+        self.assertTrue(User.objects.filter(username="not-in-the-source").exists())
+
+    def test_group_deletion(self):
+        """Test group deletion"""
+        group = Group.objects.create(name="not-in-the-source")
+        GroupLDAPSourceConnection.objects.create(
+            group=group, source=self.source, identifier="not-in-the-source"
+        )
+        self.source.object_uniqueness_field = "uid"
+        self.source.group_object_filter = "(objectClass=groupOfNames)"
+        self.source.delete_not_found_objects = True
+        self.source.save()
+
+        connection = MagicMock(return_value=mock_slapd_connection(LDAP_PASSWORD))
+        with patch("authentik.sources.ldap.models.LDAPSource.connection", connection):
+            ldap_sync_all.delay().get()
+        self.assertFalse(Group.objects.filter(name="not-in-the-source").exists())
+
+    def test_group_deletion_still_in_source(self):
+        """Test that group is not deleted if it's still in the source"""
+        groupname = group_in_slapd_cn
+        identifier = group_in_slapd_uid
+        group = Group.objects.create(name=groupname)
+        GroupLDAPSourceConnection.objects.create(
+            group=group, source=self.source, identifier=identifier
+        )
+        self.source.object_uniqueness_field = "uid"
+        self.source.group_object_filter = "(objectClass=groupOfNames)"
+        self.source.delete_not_found_objects = True
+        self.source.save()
+
+        connection = MagicMock(return_value=mock_slapd_connection(LDAP_PASSWORD))
+        with patch("authentik.sources.ldap.models.LDAPSource.connection", connection):
+            ldap_sync_all.delay().get()
+        self.assertTrue(Group.objects.filter(name=groupname).exists())
+
+    def test_group_deletion_no_sync(self):
+        """Test that group is not deleted if sync_groups is False"""
+        group = Group.objects.create(name="not-in-the-source")
+        GroupLDAPSourceConnection.objects.create(
+            group=group, source=self.source, identifier="not-in-the-source"
+        )
+        self.source.object_uniqueness_field = "uid"
+        self.source.group_object_filter = "(objectClass=groupOfNames)"
+        self.source.delete_not_found_objects = True
+        self.source.sync_groups = False
+        self.source.save()
+
+        connection = MagicMock(return_value=mock_slapd_connection(LDAP_PASSWORD))
+        with patch("authentik.sources.ldap.models.LDAPSource.connection", connection):
+            ldap_sync_all.delay().get()
+        self.assertTrue(Group.objects.filter(name="not-in-the-source").exists())
+
+    def test_group_deletion_no_delete(self):
+        """Test that group is not deleted if delete_not_found_objects is False"""
+        group = Group.objects.create(name="not-in-the-source")
+        GroupLDAPSourceConnection.objects.create(
+            group=group, source=self.source, identifier="not-in-the-source"
+        )
+        self.source.object_uniqueness_field = "uid"
+        self.source.group_object_filter = "(objectClass=groupOfNames)"
+        self.source.save()
+
+        connection = MagicMock(return_value=mock_slapd_connection(LDAP_PASSWORD))
+        with patch("authentik.sources.ldap.models.LDAPSource.connection", connection):
+            ldap_sync_all.delay().get()
+        self.assertTrue(Group.objects.filter(name="not-in-the-source").exists())
+
+    def test_batch_deletion(self):
+        """Test batch deletion"""
+        BATCH_SIZE = DELETE_CHUNK_SIZE + 1
+        for i in range(BATCH_SIZE):
+            user = User.objects.create_user(username=f"not-in-the-source-{i}")
+            group = Group.objects.create(name=f"not-in-the-source-{i}")
+            group.users.add(user)
+            UserLDAPSourceConnection.objects.create(
+                user=user, source=self.source, identifier=f"not-in-the-source-{i}-user"
+            )
+            GroupLDAPSourceConnection.objects.create(
+                group=group, source=self.source, identifier=f"not-in-the-source-{i}-group"
+            )
+        self.source.object_uniqueness_field = "uid"
+        self.source.group_object_filter = "(objectClass=groupOfNames)"
+        self.source.delete_not_found_objects = True
+        self.source.save()
+
+        connection = MagicMock(return_value=mock_slapd_connection(LDAP_PASSWORD))
+        with patch("authentik.sources.ldap.models.LDAPSource.connection", connection):
+            ldap_sync_all.delay().get()
+
+        self.assertFalse(User.objects.filter(username__startswith="not-in-the-source").exists())
+        self.assertFalse(Group.objects.filter(name__startswith="not-in-the-source").exists())

blueprints/schema.json

@@ -8180,6 +8180,11 @@
                     "type": "boolean",
                     "title": "Lookup groups from user",
                     "description": "Lookup group membership based on a user attribute instead of a group attribute. This allows nested group resolution on systems like FreeIPA and Active Directory"
+                },
+                "delete_not_found_objects": {
+                    "type": "boolean",
+                    "title": "Delete not found objects",
+                    "description": "Delete authentik users and groups which were previously supplied by this source, but are now missing from it."
                 }
             },
             "required": []

schema.yml

@@ -28473,6 +28473,10 @@ paths:
         schema:
           type: string
           format: uuid
+      - in: query
+        name: delete_not_found_objects
+        schema:
+          type: boolean
       - in: query
         name: enabled
         schema:
@@ -47922,6 +47926,10 @@ components:
           description: Lookup group membership based on a user attribute instead of
             a group attribute. This allows nested group resolution on systems like
             FreeIPA and Active Directory
+        delete_not_found_objects:
+          type: boolean
+          description: Delete authentik users and groups which were previously supplied
+            by this source, but are now missing from it.
       required:
       - base_dn
       - component
@@ -48123,6 +48131,10 @@ components:
           description: Lookup group membership based on a user attribute instead of
             a group attribute. This allows nested group resolution on systems like
             FreeIPA and Active Directory
+        delete_not_found_objects:
+          type: boolean
+          description: Delete authentik users and groups which were previously supplied
+            by this source, but are now missing from it.
       required:
       - base_dn
       - name
@@ -53456,6 +53468,10 @@ components:
           description: Lookup group membership based on a user attribute instead of
             a group attribute. This allows nested group resolution on systems like
             FreeIPA and Active Directory
+        delete_not_found_objects:
+          type: boolean
+          description: Delete authentik users and groups which were previously supplied
+            by this source, but are now missing from it.
     PatchedLicenseRequest:
       type: object
       description: License Serializer

web/src/admin/sources/ldap/LDAPSourceForm.ts

@@ -148,6 +148,26 @@ export class LDAPSourceForm extends BaseSourceForm<LDAPSource> {
                     <span class="pf-c-switch__label">${msg("Sync groups")}</span>
                 </label>
             </ak-form-element-horizontal>
+            <ak-form-element-horizontal name="deleteNotFoundObjects">
+                <label class="pf-c-switch">
+                    <input
+                        class="pf-c-switch__input"
+                        type="checkbox"
+                        ?checked=${this.instance?.deleteNotFoundObjects ?? false}
+                    />
+                    <span class="pf-c-switch__toggle">
+                        <span class="pf-c-switch__toggle-icon">
+                            <i class="fas fa-check" aria-hidden="true"></i>
+                        </span>
+                    </span>
+                    <span class="pf-c-switch__label">${msg("Delete Not Found Objects")}</span>
+                </label>
+                <p class="pf-c-form__helper-text">
+                    ${msg(
+                        "Delete authentik users and groups which were previously supplied by this source, but are now missing from it.",
+                    )}
+                </p>
+            </ak-form-element-horizontal>
             <ak-form-group .expanded=${true}>
                 <span slot="header"> ${msg("Connection settings")} </span>
                 <div slot="body" class="pf-c-form">