🐛[#3423] Fix 500 error on import

Ignores service fetch config on import, so existing exports can be imported.

The cross instance case is not trivial: Services and config ids' may
point to different things.

We'd need to define equality for ServiceFetchConfiguration and Service.
And user interaction on mismatches.

Also, Services can (and probably will) contain credentials or tokens.
These should probably not end up in some zipfile on someone's proverbial
USB-stick.

See #2683

Backport-of: #3458

src/openforms/forms/tests/test_copy.py

@@ -12,11 +12,13 @@
 from openforms.accounts.tests.factories import SuperUserFactory, TokenFactory
 from openforms.tests.utils import NOOP_CACHES
 from openforms.variables.constants import FormVariableSources
+from openforms.variables.tests.factories import ServiceFetchConfigurationFactory
 
 from ..models import Form, FormDefinition, FormStep, FormVariable
 from .factories import (
     FormDefinitionFactory,
     FormFactory,
+    FormLogicFactory,
     FormStepFactory,
     FormVariableFactory,
 )
@@ -201,7 +203,7 @@ def setUpTestData(cls):
         cls.token = TokenFactory(user=user)
 
     def test_copy_form_with_variables(self):
-        form = FormFactory.create(slug="test-copying-with-vars")
+        form: Form = FormFactory.create(slug="test-copying-with-vars")
         FormStepFactory.create(
             form=form,
             form_definition__configuration={
@@ -218,11 +220,26 @@ def test_copy_form_with_variables(self):
             },
         )
         FormVariableFactory.create(
-            form=form, source=FormVariableSources.user_defined, key="bla"
+            form=form,
+            source=FormVariableSources.user_defined,
+            key="bla",
+            service_fetch_configuration=ServiceFetchConfigurationFactory.create(),
+        )
+        FormLogicFactory.create(
+            form=form,
+            json_logic_trigger={"!": {"var": "bla"}},
+            is_advanced=True,
+            actions=[
+                {
+                    "action": {"type": "fetch-from-service", "value": ""},
+                    "variable": "bla",
+                }
+            ],
         )
 
         self.assertEqual(1, Form.objects.count())
         self.assertEqual(3, FormVariable.objects.filter(form=form).count())
+        self.assertEqual(form.formlogic_set.count(), 1)
 
         url = reverse("api:form-copy", args=(form.uuid,))
         response = self.client.post(
@@ -245,3 +262,4 @@ def test_copy_form_with_variables(self):
         self.assertEqual(
             1, variables_copy.filter(source=FormVariableSources.user_defined).count()
         )
+        self.assertEqual(form_copy.formlogic_set.count(), 1)

src/openforms/forms/tests/test_import_export.py

@@ -145,13 +145,21 @@ def test_import(self):
         # fetch configurations are not exported (yet)
         # but shouldn't break export - import
         fetch_config = ServiceFetchConfigurationFactory.create()
+        far_fetched = FormVariableFactory.create(
+            form=form,
+            user_defined=True,
+            name="far_fetched",
+            key="farFetched",
+            service_fetch_configuration=fetch_config,
+        )
         FormLogicFactory.create(
             form=form,
-            json_logic_trigger={"!": {"var": "test-user-defined"}},
+            json_logic_trigger={"!": {"var": "farFetched"}},
+            is_advanced=True,
             actions=[
                 {
-                    "action": {"type": "fetch-from-service", "value": fetch_config.pk},
-                    "variable": "test-user-defined",
+                    "action": {"type": "fetch-from-service", "value": ""},
+                    "variable": "farFetched",
                 }
             ],
         )
@@ -177,6 +185,7 @@ def test_import(self):
         call_command("export", form.pk, self.filepath)
 
         # attempt to break ForeignKey constraint
+        far_fetched.delete()
         fetch_config.delete()
 
         old_form_definition_slug = form_definition.slug
@@ -231,7 +240,12 @@ def test_import(self):
         user_defined_vars = FormVariable.objects.filter(
             source=FormVariableSources.user_defined
         )
-        self.assertEqual(2, user_defined_vars.count())
+
+        # assert 3 user_defined_vars
+        # 1. original test-user-defined
+        # 2. imported test-user-defined
+        # 3. imported far_fetched (but without service_fetch_configuration)
+        self.assertEqual(user_defined_vars.count(), 3)
 
         form_logics = FormLogic.objects.all()
         self.assertEqual(4, form_logics.count())

src/openforms/forms/utils.py

@@ -218,6 +218,12 @@ def import_form_data(
                         },
                     }
                 )
+                if "service_fetch_configuration" in entry:
+                    # The transferring between systems case is very tricky
+                    # better not import these, we don't know where this came from.
+                    # services and ids may point to different things
+                    # in different OF instances.
+                    del entry["service_fetch_configuration"]
 
             if resource == "formLogic":
                 # by now, the form resource has been created (or it was an existing one)

src/openforms/variables/tests/factories.py

@@ -7,6 +7,7 @@
 
 class ServiceFetchConfigurationFactory(factory.django.DjangoModelFactory):
     service = factory.SubFactory(ServiceFactory)
+    name = factory.Sequence(lambda n: f"Service Fetch Config #{n}")
 
     class Meta:
         model = ServiceFetchConfiguration