fix: assign fallback tenant during imports

README.md

@@ -113,7 +113,9 @@ Der Exportgraph berücksichtigt installierte, mandantenbezogene Modelle und
 Dateien aus NetBox-SLM, Netbox-DokiWiki und NetBox-VM-Import. Private oder
 temporäre Plugin-Modelle werden nicht exportiert. Die von Netbox-Utilities
 erzwungene Mandantenpflicht wird beim Import berücksichtigt: Das Zielobjekt wird
-erst gespeichert, nachdem sein Mandant importiert und zugeordnet wurde.
+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.
 
 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 = "0.3.3"
+    version = "0.3.4"
     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": "0.3.3",
+        "plugin_version": "0.3.4",
         "scope": {
             "type": scope_type,
             "source_pk": str(scope_id),

netbox_export/services/importer.py

@@ -17,8 +17,8 @@ from .archive import ParsedArchive
 from .codec import SKIP_FIELD_NAMES, decode_scalar, generic_foreign_keys
 from .exceptions import ArchiveValidationError, ExportImportError, ImportConflictError
 from .plugin_compat import (
-    netbox_utilities_tenant_required,
-    relation_required_before_save,
+    PluginCompatibility,
+    is_tenant_relation,
 )
 from .references import MISSING_REFERENCE, ReferenceResolver
 
@@ -244,17 +244,17 @@ def _field_kwargs(model, record, resolver, *, tenant_required: bool):
         field = valid_fields.get(name)
         if not isinstance(field, (models.ForeignKey, models.OneToOneField)):
             continue
-        required_before_save = relation_required_before_save(field, tenant_required=tenant_required)
+        tenant_relation = is_tenant_relation(field)
         value, available = resolver.resolve(spec)
         if available:
             if value is MISSING_REFERENCE:
-                if required_before_save or (not field.null and not field.has_default()):
+                if not field.null and not field.has_default():
                     missing_required.append(name)
-            elif value is None and required_before_save:
-                missing_required.append(name)
+            elif value is None and tenant_relation and tenant_required:
+                continue
             else:
                 kwargs[name] = value
-        elif field.null and not required_before_save:
+        elif field.null and not tenant_relation:
             unresolved.append((name, spec))
         else:
             return None, [], [], []
@@ -352,7 +352,7 @@ def import_archive(parsed: ParsedArchive, *, conflict_strategy: str, dry_run: bo
     report = ImportReport(dry_run=dry_run, warnings=list(parsed.warnings))
     resolved = {}
     resolver = ReferenceResolver(resolved, report.warnings, _model_for)
-    tenant_required = netbox_utilities_tenant_required()
+    compatibility = PluginCompatibility(report.warnings, dry_run=dry_run)
     deferred_relations = []
     deferred_generic = []
     deferred_values = []
@@ -367,7 +367,7 @@ def import_archive(parsed: ParsedArchive, *, conflict_strategy: str, dry_run: bo
                 for record_id, record in list(pending.items()):
                     model = _model_for(record["model"])
                     kwargs, unresolved, unresolved_value_fields, missing_required = _field_kwargs(
-                        model, record, resolver, tenant_required=tenant_required
+                        model, record, resolver, tenant_required=compatibility.tenant_required
                     )
                     if kwargs is None:
                         continue
@@ -397,7 +397,7 @@ def import_archive(parsed: ParsedArchive, *, conflict_strategy: str, dry_run: bo
                             progressed = True
                             continue
                         _set_files(obj, record, parsed.assets, saved_files, dry_run=dry_run)
-                        obj.save()
+                        compatibility.save(obj)
                         action = "updated" if existing is not None else "created"
                         writable.add(record_id)
                         deferred_relations.extend((record_id, name, spec) for name, spec in unresolved)
@@ -428,7 +428,7 @@ def import_archive(parsed: ParsedArchive, *, conflict_strategy: str, dry_run: bo
                     continue
                 obj = resolved[record_id]
                 setattr(obj, name, value)
-                obj.save(update_fields=[name])
+                compatibility.save(obj, update_fields=[name])
 
             for record_id, name, spec in deferred_generic:
                 if record_id not in writable:
@@ -441,7 +441,7 @@ def import_archive(parsed: ParsedArchive, *, conflict_strategy: str, dry_run: bo
                 obj = resolved[record_id]
                 setattr(obj, name, value)
                 field = next(field for field in generic_foreign_keys(type(obj)) if field.name == name)
-                obj.save(update_fields=[field.ct_field, field.fk_field])
+                compatibility.save(obj, update_fields=[field.ct_field, field.fk_field])
 
             for record_id, name, encoded in deferred_values:
                 if record_id not in writable:
@@ -451,7 +451,7 @@ def import_archive(parsed: ParsedArchive, *, conflict_strategy: str, dry_run: bo
                     raise ArchiveValidationError(f"Custom-Field-Referenz {name} für {record_id} fehlt.")
                 obj = resolved[record_id]
                 setattr(obj, name, value)
-                obj.save(update_fields=[name])
+                compatibility.save(obj, update_fields=[name])
 
             for record_id, record in records.items():
                 if record_id in writable:

netbox_export/services/plugin_compat.py

@@ -1,5 +1,12 @@
 from __future__ import annotations
 
+from django.apps import apps
+from django.core.exceptions import FieldDoesNotExist, ValidationError
+
+AUTO_IMPORT_TENANT_NAME = "Auto-Import"
+AUTO_IMPORT_TENANT_SLUG = "auto-import"
+MISSING_TENANT_MESSAGE = "Für dieses Objekt muss ein Mandant angegeben werden."
+
 
 def netbox_utilities_tenant_required() -> bool:
     """Return the effective tenant policy without requiring the optional plugin."""
@@ -10,8 +17,89 @@ def netbox_utilities_tenant_required() -> bool:
     return bool(tenant_required())
 
 
-def relation_required_before_save(field, *, tenant_required: bool) -> bool:
-    if not tenant_required or field.name != "tenant":
+def is_tenant_relation(field) -> bool:
+    if field.name != "tenant":
         return False
     related_model = getattr(field.remote_field, "model", None)
     return getattr(getattr(related_model, "_meta", None), "label_lower", None) == "tenancy.tenant"
+
+
+class PluginCompatibility:
+    def __init__(
+        self,
+        warnings,
+        *,
+        dry_run: bool,
+        tenant_required: bool | None = None,
+        tenant_model_loader=None,
+    ):
+        self.warnings = warnings
+        self.dry_run = dry_run
+        self.tenant_required = (
+            netbox_utilities_tenant_required() if tenant_required is None else tenant_required
+        )
+        self.tenant_model_loader = tenant_model_loader or (lambda: apps.get_model("tenancy.tenant"))
+        self._fallback_tenant = None
+
+    @staticmethod
+    def _supports_tenant(obj) -> bool:
+        try:
+            field = obj._meta.get_field("tenant")
+        except FieldDoesNotExist:
+            return False
+        return is_tenant_relation(field)
+
+    @staticmethod
+    def _is_missing_tenant_error(exc: ValidationError) -> bool:
+        return MISSING_TENANT_MESSAGE in exc.messages
+
+    def _auto_import_tenant(self):
+        if self._fallback_tenant is not None:
+            return self._fallback_tenant
+
+        model = self.tenant_model_loader()
+        tenant = model._default_manager.filter(name=AUTO_IMPORT_TENANT_NAME).order_by("pk").first()
+        created = tenant is None
+        if tenant is None:
+            slug = AUTO_IMPORT_TENANT_SLUG
+            suffix = 2
+            while model._default_manager.filter(slug=slug).exists():
+                slug = f"{AUTO_IMPORT_TENANT_SLUG}-{suffix}"
+                suffix += 1
+            tenant = model._default_manager.create(name=AUTO_IMPORT_TENANT_NAME, slug=slug)
+
+        if self.dry_run:
+            message = (
+                'Für den Prüflauf wurde der Mandant "Auto-Import" automatisch als Ersatzmandant '
+                "verwendet; er wird nicht dauerhaft angelegt oder geändert."
+            )
+        elif created:
+            message = (
+                'Der Mandant "Auto-Import" wurde automatisch erstellt und Objekten ohne '
+                "auflösbaren Mandanten zugewiesen."
+            )
+        else:
+            message = (
+                'Der vorhandene Mandant "Auto-Import" wurde automatisch für Objekte ohne '
+                "auflösbaren Mandanten ausgewählt."
+            )
+        self.warnings.append(message)
+        self._fallback_tenant = tenant
+        return tenant
+
+    def _assign_fallback_tenant(self, obj, *, force: bool = False) -> bool:
+        if getattr(obj, "tenant_id", None) is not None or not self._supports_tenant(obj):
+            return False
+        if not force and not self.tenant_required:
+            return False
+        obj.tenant = self._auto_import_tenant()
+        return True
+
+    def save(self, obj, **kwargs):
+        self._assign_fallback_tenant(obj)
+        try:
+            return obj.save(**kwargs)
+        except ValidationError as exc:
+            if not self._is_missing_tenant_error(exc) or not self._assign_fallback_tenant(obj, force=True):
+                raise
+            return obj.save(**kwargs)

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "netbox-export"
-version = "0.3.3"
+version = "0.3.4"
 description = "Portable ZIP export and import for scoped NetBox data"
 readme = "README.md"
 requires-python = ">=3.12"

tests/test_importer_plugin_compat.py

@@ -23,7 +23,7 @@ def tenant_record():
     }
 
 
-def test_unresolved_tenant_blocks_initial_save_when_netbox_utilities_requires_it():
+def test_unresolved_tenant_always_blocks_initial_save():
     resolver = ReferenceResolver({}, [], lambda label: None)
 
     kwargs, unresolved, unresolved_values, missing_required = _field_kwargs(
@@ -39,7 +39,7 @@ def test_unresolved_tenant_blocks_initial_save_when_netbox_utilities_requires_it
     assert missing_required == []
 
 
-def test_unresolved_optional_tenant_remains_deferred_without_requirement():
+def test_unresolved_tenant_also_blocks_when_policy_detection_is_unavailable():
     resolver = ReferenceResolver({}, [], lambda label: None)
 
     kwargs, unresolved, unresolved_values, missing_required = _field_kwargs(
@@ -49,7 +49,7 @@ def test_unresolved_optional_tenant_remains_deferred_without_requirement():
         tenant_required=False,
     )
 
-    assert kwargs == {}
-    assert unresolved == [("tenant", {"ref": "tenancy.tenant:23"})]
+    assert kwargs is None
+    assert unresolved == []
     assert unresolved_values == []
     assert missing_required == []

tests/test_plugin_compat.py

@@ -1,26 +1,133 @@
 from types import SimpleNamespace
 
-from netbox_export.services.plugin_compat import relation_required_before_save
+from django.core.exceptions import FieldDoesNotExist, ValidationError
+
+from netbox_export.services.plugin_compat import (
+    MISSING_TENANT_MESSAGE,
+    PluginCompatibility,
+    is_tenant_relation,
+)
 
 
-def relation_field(name, related_label):
+def relation_field(name="tenant", related_label="tenancy.tenant"):
     related_model = SimpleNamespace(_meta=SimpleNamespace(label_lower=related_label))
     return SimpleNamespace(name=name, remote_field=SimpleNamespace(model=related_model))
 
 
-def test_tenant_relation_is_resolved_before_initial_save_when_required():
-    field = relation_field("tenant", "tenancy.tenant")
+class FakeQuerySet:
+    def __init__(self, result=None, exists=False):
+        self.result = result
+        self._exists = exists
 
-    assert relation_required_before_save(field, tenant_required=True) is True
+    def order_by(self, *fields):
+        return self
+
+    def first(self):
+        return self.result
+
+    def exists(self):
+        return self._exists
 
 
-def test_tenant_relation_can_still_be_deferred_when_policy_is_disabled():
-    field = relation_field("tenant", "tenancy.tenant")
+class FakeTenantManager:
+    def __init__(self, existing=None):
+        self.existing = existing
+        self.created = []
 
-    assert relation_required_before_save(field, tenant_required=False) is False
+    def filter(self, **lookup):
+        if "name" in lookup:
+            return FakeQuerySet(self.existing)
+        return FakeQuerySet(exists=False)
+
+    def create(self, **values):
+        tenant = SimpleNamespace(pk=42, **values)
+        self.created.append(tenant)
+        return tenant
 
 
-def test_unrelated_relation_is_not_affected_by_tenant_policy():
-    field = relation_field("site", "dcim.site")
+class FakeTenantModel:
+    _default_manager = FakeTenantManager()
 
-    assert relation_required_before_save(field, tenant_required=True) is False
+
+class FakeMeta:
+    def get_field(self, name):
+        if name != "tenant":
+            raise FieldDoesNotExist(name)
+        return relation_field()
+
+
+class TenantRequiredObject:
+    _meta = FakeMeta()
+
+    def __init__(self):
+        self.tenant_id = None
+        self.save_calls = 0
+
+    @property
+    def tenant(self):
+        return None
+
+    @tenant.setter
+    def tenant(self, value):
+        self.tenant_id = value.pk
+
+    def save(self, **kwargs):
+        self.save_calls += 1
+        if self.tenant_id is None:
+            raise ValidationError(MISSING_TENANT_MESSAGE)
+
+
+def test_identifies_tenant_relation():
+    assert is_tenant_relation(relation_field()) is True
+    assert is_tenant_relation(relation_field("site", "dcim.site")) is False
+
+
+def test_creates_and_assigns_auto_import_tenant_when_policy_is_active():
+    manager = FakeTenantManager()
+    tenant_model = type("TenantModel", (), {"_default_manager": manager})
+    warnings = []
+    compatibility = PluginCompatibility(
+        warnings,
+        dry_run=False,
+        tenant_required=True,
+        tenant_model_loader=lambda: tenant_model,
+    )
+    obj = TenantRequiredObject()
+
+    compatibility.save(obj)
+
+    assert obj.tenant_id == 42
+    assert obj.save_calls == 1
+    assert len(manager.created) == 1
+    assert warnings == [
+        (
+            'Der Mandant "Auto-Import" wurde automatisch erstellt und Objekten ohne '
+            'auflösbaren Mandanten zugewiesen.'
+        )
+    ]
+
+
+def test_validation_error_forces_fallback_for_older_plugin_versions():
+    existing = SimpleNamespace(pk=7, name="Auto-Import", slug="auto-import")
+    manager = FakeTenantManager(existing=existing)
+    tenant_model = type("TenantModel", (), {"_default_manager": manager})
+    warnings = []
+    compatibility = PluginCompatibility(
+        warnings,
+        dry_run=False,
+        tenant_required=False,
+        tenant_model_loader=lambda: tenant_model,
+    )
+    obj = TenantRequiredObject()
+
+    compatibility.save(obj)
+
+    assert obj.tenant_id == 7
+    assert obj.save_calls == 2
+    assert manager.created == []
+    assert warnings == [
+        (
+            'Der vorhandene Mandant "Auto-Import" wurde automatisch für Objekte ohne '
+            'auflösbaren Mandanten ausgewählt.'
+        )
+    ]