[#2566] Persist originating service on zgw clients

To support multiple zgw backends, we frequently need to determine
which backend to query for which resource. As a first step to
keeping better track of where ZGW objects come from, in this
commit we persist the zgw service used to configure a client
on the client object, so that we can later fetch and persist
this service to facilitate easier target backend resolution.

src/open_inwoner/openzaak/clients.py

@@ -13,6 +13,7 @@
 from zgw_consumers.api_models.catalogi import Catalogus
 from zgw_consumers.api_models.constants import RolOmschrijving, RolTypes
 from zgw_consumers.client import build_client
+from zgw_consumers.models import Service
 from zgw_consumers.service import pagination_helper
 
 from open_inwoner.openzaak.api_models import InformatieObject
@@ -39,7 +40,18 @@
 logger = logging.getLogger(__name__)
 
 
-class ZakenClient(APIClient):
+class ZgwAPIClient(APIClient):
+    """A client for interacting with ZGW services."""
+
+    configured_from: Service
+    """The Service instance used to configure this client."""
+
+    def __init__(self, *args, **kwargs):
+        self.configured_from = kwargs.pop("configured_from")
+        super().__init__(*args, **kwargs)
+
+
+class ZakenClient(ZgwAPIClient):
     def fetch_cases(
         self,
         user_bsn: str | None = None,
@@ -424,7 +436,7 @@ def connect_case_with_document(
         return data
 
 
-class CatalogiClient(APIClient):
+class CatalogiClient(ZgwAPIClient):
     # not cached because only used by tools,
     # and because caching (stale) listings can break lookups
     def fetch_status_types_no_cache(self, case_type_url: str) -> list[StatusType]:
@@ -583,7 +595,7 @@ def fetch_single_information_object_type(
         return information_object_type
 
 
-class DocumentenClient(APIClient):
+class DocumentenClient(ZgwAPIClient):
     def _fetch_single_information_object(
         self, *, url: str | None = None, uuid: str | None = None
     ) -> InformatieObject | None:
@@ -645,7 +657,7 @@ def upload_document(
         return data
 
 
-class FormClient(APIClient):
+class FormClient(ZgwAPIClient):
     def fetch_open_submissions(self, bsn: str) -> list[OpenSubmission]:
         if not bsn:
             return []
@@ -696,7 +708,9 @@ def _build_zgw_client(type_: ZgwClientType) -> ZgwClient | None:
     if client_class := services_to_client_mapping.get(type_):
         service = getattr(config, f"{type_}_service")
         if service:
-            client = build_client(service, client_factory=client_class)
+            client = build_client(
+                service, client_factory=client_class, configured_from=service
+            )
             return client
 
     logger.warning("no service defined for %s", type_)

src/open_inwoner/openzaak/tests/test_clients.py

@@ -0,0 +1,28 @@
+from django.test import TestCase
+
+from zgw_consumers.constants import APITypes
+from zgw_consumers.models import Service
+
+from open_inwoner.openzaak.clients import (
+    build_catalogi_client,
+    build_documenten_client,
+    build_forms_client,
+    build_zaken_client,
+)
+from open_inwoner.openzaak.tests.factories import ZGWApiGroupConfigFactory
+
+
+class ClientFactoryTestCase(TestCase):
+    def setUp(self):
+        ZGWApiGroupConfigFactory()
+
+    def test_originating_service_is_persisted_on_client(self):
+        for factory, api_type in (
+            (build_forms_client, APITypes.orc),
+            (build_zaken_client, APITypes.zrc),
+            (build_documenten_client, APITypes.drc),
+            (build_catalogi_client, APITypes.ztc),
+        ):
+            client = factory()
+            self.assertIsInstance(client.configured_from, Service)
+            self.assertEqual(client.configured_from.api_type, api_type)