providers/scim: add comparison with existing group on update and delta update users

authentik/lib/utils/http.py

@@ -21,7 +21,14 @@ class DebugSession(Session):
 
     def send(self, req: PreparedRequest, *args, **kwargs):
         request_id = str(uuid4())
-        LOGGER.debug("HTTP request sent", uid=request_id, path=req.path_url, headers=req.headers)
+        LOGGER.debug(
+            "HTTP request sent",
+            uid=request_id,
+            url=req.url,
+            method=req.method,
+            headers=req.headers,
+            body=req.body,
+        )
         resp = super().send(req, *args, **kwargs)
         LOGGER.debug(
             "HTTP response received",

authentik/providers/scim/clients/groups.py

@@ -2,9 +2,10 @@
 
 from itertools import batched
 
+from django.db import transaction
 from pydantic import ValidationError
 from pydanticscim.group import GroupMember
-from pydanticscim.responses import PatchOp, PatchOperation
+from pydanticscim.responses import PatchOp
 
 from authentik.core.models import Group
 from authentik.lib.sync.mapper import PropertyMappingManager
@@ -19,7 +20,7 @@
 from authentik.providers.scim.clients.exceptions import (
     SCIMRequestException,
 )
-from authentik.providers.scim.clients.schema import SCIM_GROUP_SCHEMA, PatchRequest
+from authentik.providers.scim.clients.schema import SCIM_GROUP_SCHEMA, PatchOperation, PatchRequest
 from authentik.providers.scim.clients.schema import Group as SCIMGroupSchema
 from authentik.providers.scim.models import (
     SCIMMapping,
@@ -104,13 +105,47 @@ def create(self, group: Group):
             provider=self.provider, group=group, scim_id=scim_id
         )
         users = list(group.users.order_by("id").values_list("id", flat=True))
-        self._patch_add_users(group, users)
+        self._patch_add_users(connection, users)
         return connection
 
     def update(self, group: Group, connection: SCIMProviderGroup):
         """Update existing group"""
         scim_group = self.to_schema(group, connection)
         scim_group.id = connection.scim_id
+        try:
+            if self._config.patch.supported:
+                return self._update_patch(group, scim_group, connection)
+            return self._update_put(group, scim_group, connection)
+        except NotFoundSyncException:
+            # Resource missing is handled by self.write, which will re-create the group
+            raise
+
+    def _update_patch(
+        self, group: Group, scim_group: SCIMGroupSchema, connection: SCIMProviderGroup
+    ):
+        """Update a group via PATCH request"""
+        # Patch group's attributes instead of replacing it and re-adding users if we can
+        self._request(
+            "PATCH",
+            f"/Groups/{connection.scim_id}",
+            json=PatchRequest(
+                Operations=[
+                    PatchOperation(
+                        op=PatchOp.replace,
+                        path=None,
+                        value=scim_group.model_dump(mode="json", exclude_unset=True),
+                    )
+                ]
+            ).model_dump(
+                mode="json",
+                exclude_unset=True,
+                exclude_none=True,
+            ),
+        )
+        return self.patch_compare_users(group)
+
+    def _update_put(self, group: Group, scim_group: SCIMGroupSchema, connection: SCIMProviderGroup):
+        """Update a group via PUT request"""
         try:
             self._request(
                 "PUT",
@@ -120,50 +155,45 @@ def update(self, group: Group, connection: SCIMProviderGroup):
                     exclude_unset=True,
                 ),
             )
-            users = list(group.users.order_by("id").values_list("id", flat=True))
-            return self._patch_add_users(group, users)
-        except NotFoundSyncException:
-            # Resource missing is handled by self.write, which will re-create the group
-            raise
+            return self.patch_compare_users(group)
         except (SCIMRequestException, ObjectExistsSyncException):
             # Some providers don't support PUT on groups, so this is mainly a fix for the initial
             # sync, send patch add requests for all the users the group currently has
-            users = list(group.users.order_by("id").values_list("id", flat=True))
-            self._patch_add_users(group, users)
-            # Also update the group name
-            return self._patch(
-                scim_group.id,
-                PatchOperation(
-                    op=PatchOp.replace,
-                    path="displayName",
-                    value=scim_group.displayName,
-                ),
-            )
+            return self._update_patch(group, scim_group, connection)
 
     def update_group(self, group: Group, action: Direction, users_set: set[int]):
         """Update a group, either using PUT to replace it or PATCH if supported"""
+        scim_group = SCIMProviderGroup.objects.filter(provider=self.provider, group=group).first()
+        if not scim_group:
+            self.logger.warning(
+                "could not sync group membership, group does not exist", group=group
+            )
+            return
         if self._config.patch.supported:
             if action == Direction.add:
-                return self._patch_add_users(group, users_set)
+                return self._patch_add_users(scim_group, users_set)
             if action == Direction.remove:
-                return self._patch_remove_users(group, users_set)
+                return self._patch_remove_users(scim_group, users_set)
         try:
             return self.write(group)
         except SCIMRequestException as exc:
             if self._config.is_fallback:
                 # Assume that provider does not support PUT and also doesn't support
                 # ServiceProviderConfig, so try PATCH as a fallback
                 if action == Direction.add:
-                    return self._patch_add_users(group, users_set)
+                    return self._patch_add_users(scim_group, users_set)
                 if action == Direction.remove:
-                    return self._patch_remove_users(group, users_set)
+                    return self._patch_remove_users(scim_group, users_set)
             raise exc
 
-    def _patch(
+    def _patch_chunked(
         self,
         group_id: str,
         *ops: PatchOperation,
     ):
+        """Helper function that chunks patch requests based on the maxOperations attribute.
+        This is not strictly according to specs but there's nothing in the schema that allows the
+        us to know what the maximum patch operations per request should be."""
         chunk_size = self._config.bulk.maxOperations
         if chunk_size < 1:
             chunk_size = len(ops)
@@ -177,24 +207,75 @@ def _patch(
                 ),
             )
 
-    def _patch_add_users(self, group: Group, users_set: set[int]):
-        """Add users in users_set to group"""
-        if len(users_set) < 1:
-            return
+    @transaction.atomic
+    def patch_compare_users(self, group: Group):
+        """Compare users with a SCIM group and add/remove any differences"""
+        # Get scim group first
         scim_group = SCIMProviderGroup.objects.filter(provider=self.provider, group=group).first()
         if not scim_group:
             self.logger.warning(
                 "could not sync group membership, group does not exist", group=group
             )
             return
+        # Get a list of all users in the authentik group
+        raw_users_should = list(group.users.order_by("id").values_list("id", flat=True))
+        # Lookup the SCIM IDs of the users
+        users_should: list[str] = list(
+            SCIMProviderUser.objects.filter(
+                user__pk__in=raw_users_should, provider=self.provider
+            ).values_list("scim_id", flat=True)
+        )
+        if len(raw_users_should) != len(users_should):
+            self.logger.warning(
+                "User count mismatch, not all users in the group are synced to SCIM yet.",
+                group=group,
+            )
+        # Get current group status
+        current_group = SCIMGroupSchema.model_validate(
+            self._request("GET", f"/Groups/{scim_group.scim_id}")
+        )
+        users_to_add = []
+        users_to_remove = []
+        # Check users currently in group and if they shouldn't be in the group and remove them
+        for user in current_group.members:
+            if user.value not in users_should:
+                users_to_remove.append(user.value)
+        # Check users that should be in the group and add them
+        for user in users_should:
+            if len([x for x in current_group.members if x.value == user]) < 1:
+                users_to_add.append(user)
+        return self._patch_chunked(
+            scim_group.scim_id,
+            *[
+                PatchOperation(
+                    op=PatchOp.add,
+                    path="members",
+                    value=[{"value": x}],
+                )
+                for x in users_to_add
+            ],
+            *[
+                PatchOperation(
+                    op=PatchOp.remove,
+                    path="members",
+                    value=[{"value": x}],
+                )
+                for x in users_to_remove
+            ],
+        )
+
+    def _patch_add_users(self, scim_group: SCIMProviderGroup, users_set: set[int]):
+        """Add users in users_set to group"""
+        if len(users_set) < 1:
+            return
         user_ids = list(
             SCIMProviderUser.objects.filter(
                 user__pk__in=users_set, provider=self.provider
             ).values_list("scim_id", flat=True)
         )
         if len(user_ids) < 1:
             return
-        self._patch(
+        self._patch_chunked(
             scim_group.scim_id,
             *[
                 PatchOperation(
@@ -206,24 +287,18 @@ def _patch_add_users(self, group: Group, users_set: set[int]):
             ],
         )
 
-    def _patch_remove_users(self, group: Group, users_set: set[int]):
+    def _patch_remove_users(self, scim_group: SCIMProviderGroup, users_set: set[int]):
         """Remove users in users_set from group"""
         if len(users_set) < 1:
             return
-        scim_group = SCIMProviderGroup.objects.filter(provider=self.provider, group=group).first()
-        if not scim_group:
-            self.logger.warning(
-                "could not sync group membership, group does not exist", group=group
-            )
-            return
         user_ids = list(
             SCIMProviderUser.objects.filter(
                 user__pk__in=users_set, provider=self.provider
             ).values_list("scim_id", flat=True)
         )
         if len(user_ids) < 1:
             return
-        self._patch(
+        self._patch_chunked(
             scim_group.scim_id,
             *[
                 PatchOperation(

authentik/providers/scim/clients/schema.py

@@ -2,6 +2,7 @@
 
 from pydantic import Field
 from pydanticscim.group import Group as BaseGroup
+from pydanticscim.responses import PatchOperation as BasePatchOperation
 from pydanticscim.responses import PatchRequest as BasePatchRequest
 from pydanticscim.responses import SCIMError as BaseSCIMError
 from pydanticscim.service_provider import Bulk as BaseBulk
@@ -68,6 +69,12 @@ class PatchRequest(BasePatchRequest):
     schemas: tuple[str] = ("urn:ietf:params:scim:api:messages:2.0:PatchOp",)
 
 
+class PatchOperation(BasePatchOperation):
+    """PatchOperation with optional path"""
+
+    path: str | None
+
+
 class SCIMError(BaseSCIMError):
     """SCIM error with optional status code"""