fix: resolve constrained relations before insert

README.md

@@ -116,6 +116,9 @@ erzwungene Mandantenpflicht wird beim Import berücksichtigt: Das Zielobjekt wir
 erst gespeichert, nachdem sein Mandant importiert und zugeordnet wurde. Ist kein
 Mandant auflösbar, wird automatisch ein vorhandener Mandant `Auto-Import`
 verwendet oder neu angelegt. Der Importbericht weist darauf hin.
+Beziehungen, die Teil einer Plugin-Datenbankprüfung sind, werden vollständig
+aufgelöst, bevor das Objekt erstmals gespeichert wird. Dies betrifft unter
+anderem die Plattformzuordnung von NetBox-SLM-Softwareinstallationen.
 
 Auf Quelle und Ziel müssen jeweils dieselben Plugin-Versionen und Migrationen
 installiert sein. Verschlüsselte Zugangsdaten von NetBox-VM-Import sind nur bei

netbox_export/__init__.py

@@ -7,7 +7,7 @@ class NetBoxExportConfig(PluginConfig):
     name = "netbox_export"
     verbose_name = "NetBox-Export"
     description = "Portable ZIP export and import for tenants and locations"
-    version = "0.3.4"
+    version = "0.3.5"
     author = "NetBox Export contributors"
     base_url = "netbox-export"
     min_version = "4.6.0"

netbox_export/services/exporter.py

@@ -39,7 +39,7 @@ def export_scope(
         "created_at": datetime.now(UTC).isoformat(),
         "source_instance": str(InstanceIdentity.local_id()),
         "source_netbox_version": getattr(getattr(settings, "RELEASE", None), "version", "4.6"),
-        "plugin_version": "0.3.4",
+        "plugin_version": "0.3.5",
         "scope": {
             "type": scope_type,
             "source_pk": str(scope_id),

netbox_export/services/importer.py

@@ -19,6 +19,7 @@ from .exceptions import ArchiveValidationError, ExportImportError, ImportConflic
 from .plugin_compat import (
     PluginCompatibility,
     is_tenant_relation,
+    relation_required_before_save,
 )
 from .references import MISSING_REFERENCE, ReferenceResolver
 
@@ -245,16 +246,19 @@ def _field_kwargs(model, record, resolver, *, tenant_required: bool):
         if not isinstance(field, (models.ForeignKey, models.OneToOneField)):
             continue
         tenant_relation = is_tenant_relation(field)
+        required_before_save = relation_required_before_save(field)
         value, available = resolver.resolve(spec)
         if available:
             if value is MISSING_REFERENCE:
-                if not field.null and not field.has_default():
+                if (required_before_save and not tenant_relation) or (
+                    not field.null and not field.has_default() and not tenant_relation
+                ):
                     missing_required.append(name)
             elif value is None and tenant_relation and tenant_required:
                 continue
             else:
                 kwargs[name] = value
-        elif field.null and not tenant_relation:
+        elif field.null and not required_before_save:
             unresolved.append((name, spec))
         else:
             return None, [], [], []

netbox_export/services/plugin_compat.py

@@ -1,7 +1,10 @@
 from __future__ import annotations
 
+from functools import cache
+
 from django.apps import apps
 from django.core.exceptions import FieldDoesNotExist, ValidationError
+from django.db import models
 
 AUTO_IMPORT_TENANT_NAME = "Auto-Import"
 AUTO_IMPORT_TENANT_SLUG = "auto-import"
@@ -24,6 +27,31 @@ def is_tenant_relation(field) -> bool:
     return getattr(getattr(related_model, "_meta", None), "label_lower", None) == "tenancy.tenant"
 
 
+def _condition_field_names(condition):
+    for child in getattr(condition, "children", ()):
+        if isinstance(child, tuple):
+            yield child[0].split("__", 1)[0]
+        else:
+            yield from _condition_field_names(child)
+
+
+@cache
+def check_constraint_field_names(model) -> frozenset[str]:
+    if model is None:
+        return frozenset()
+    names = set()
+    for constraint in model._meta.constraints:
+        if isinstance(constraint, models.CheckConstraint):
+            names.update(_condition_field_names(constraint.condition))
+    return frozenset(names)
+
+
+def relation_required_before_save(field) -> bool:
+    return is_tenant_relation(field) or field.name in check_constraint_field_names(
+        getattr(field, "model", None)
+    )
+
+
 class PluginCompatibility:
     def __init__(
         self,

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "netbox-export"
-version = "0.3.4"
+version = "0.3.5"
 description = "Portable ZIP export and import for scoped NetBox data"
 readme = "README.md"
 requires-python = ">=3.12"

tests/test_importer_plugin_compat.py

@@ -1,3 +1,5 @@
+from typing import ClassVar
+
 from django.db import models
 
 from netbox_export.services.importer import _field_kwargs
@@ -16,6 +18,24 @@ class TenantManagedObject(models.Model):
         app_label = "compat_tests"
 
 
+class Platform(models.Model):
+    class Meta:
+        app_label = "compat_tests"
+
+
+class ConstrainedInstallation(models.Model):
+    platform = models.ForeignKey(Platform, on_delete=models.PROTECT, null=True)
+
+    class Meta:
+        app_label = "compat_tests"
+        constraints: ClassVar[list] = [
+            models.CheckConstraint(
+                condition=models.Q(platform__isnull=False),
+                name="compat_tests_installation_platform",
+            )
+        ]
+
+
 def tenant_record():
     return {
         "fields": {},
@@ -53,3 +73,23 @@ def test_unresolved_tenant_also_blocks_when_policy_detection_is_unavailable():
     assert unresolved == []
     assert unresolved_values == []
     assert missing_required == []
+
+
+def test_unresolved_relation_in_check_constraint_blocks_initial_save():
+    resolver = ReferenceResolver({}, [], lambda label: None)
+    record = {
+        "fields": {},
+        "relations": {"platform": {"ref": "compat_tests.platform:5"}},
+    }
+
+    kwargs, unresolved, unresolved_values, missing_required = _field_kwargs(
+        ConstrainedInstallation,
+        record,
+        resolver,
+        tenant_required=False,
+    )
+
+    assert kwargs is None
+    assert unresolved == []
+    assert unresolved_values == []
+    assert missing_required == []

tests/test_plugin_compat.py

@@ -1,11 +1,14 @@
 from types import SimpleNamespace
 
 from django.core.exceptions import FieldDoesNotExist, ValidationError
+from django.db import models
 
 from netbox_export.services.plugin_compat import (
     MISSING_TENANT_MESSAGE,
     PluginCompatibility,
+    check_constraint_field_names,
     is_tenant_relation,
+    relation_required_before_save,
 )
 
 
@@ -82,6 +85,22 @@ def test_identifies_tenant_relation():
     assert is_tenant_relation(relation_field("site", "dcim.site")) is False
 
 
+def test_identifies_relations_used_by_check_constraint():
+    constraint = models.CheckConstraint(
+        condition=(
+            models.Q(device__isnull=False, virtualmachine__isnull=True)
+            | models.Q(device__isnull=True, virtualmachine__isnull=False)
+        ),
+        name="platform",
+    )
+    model = type("ConstrainedModel", (), {"_meta": SimpleNamespace(constraints=[constraint])})
+    field = relation_field("device", "dcim.device")
+    field.model = model
+
+    assert check_constraint_field_names(model) == frozenset({"device", "virtualmachine"})
+    assert relation_required_before_save(field) is True
+
+
 def test_creates_and_assigns_auto_import_tenant_when_policy_is_active():
     manager = FakeTenantManager()
     tenant_model = type("TenantModel", (), {"_default_manager": manager})