Fix and test data migration error from DAB RBAC (#15138)

* Fix and test data migration error from DAB RBAC

* Fix up migration test

* Fix custom method bug

* Fix another fat fingered bug

awx/main/migrations/_dab_rbac.py

@@ -140,6 +140,17 @@ def get_permissions_for_role(role_field, children_map, apps):
     return perm_list
 
 
+def model_class(ct, apps):
+    """
+    You can not use model methods in migrations, so this duplicates
+    what ContentType.model_class does, using current apps
+    """
+    try:
+        return apps.get_model(ct.app_label, ct.model)
+    except LookupError:
+        return None
+
+
 def migrate_to_new_rbac(apps, schema_editor):
     """
     This method moves the assigned permissions from the old rbac.py models
@@ -197,7 +208,7 @@ def migrate_to_new_rbac(apps, schema_editor):
             role_definition = managed_definitions[permissions]
         else:
             action = role.role_field.rsplit('_', 1)[0]  # remove the _field ending of the name
-            role_definition_name = f'{role.content_type.model_class().__name__} {action.title()}'
+            role_definition_name = f'{model_class(role.content_type, apps).__name__} {action.title()}'
 
             description = role_descriptions[role.role_field]
             if type(description) == dict:

awx/main/tests/functional/test_migrations.py

@@ -1,6 +1,7 @@
 import pytest
 
 from django_test_migrations.plan import all_migrations, nodes_to_tuples
+from django.utils.timezone import now
 
 """
 Most tests that live in here can probably be deleted at some point. They are mainly
@@ -68,3 +69,19 @@ def test_receptor_address(self, migrator):
         bar_peers = bar.peers.all()
         assert len(bar_peers) == 1
         assert fooaddr in bar_peers
+
+    def test_migrate_DAB_RBAC(self, migrator):
+        old_state = migrator.apply_initial_migration(('main', '0190_alter_inventorysource_source_and_more'))
+        Organization = old_state.apps.get_model('main', 'Organization')
+        User = old_state.apps.get_model('auth', 'User')
+
+        org = Organization.objects.create(name='arbitrary-org', created=now(), modified=now())
+        user = User.objects.create(username='random-user')
+        org.read_role.members.add(user)
+
+        new_state = migrator.apply_tested_migration(
+            ('main', '0192_custom_roles'),
+        )
+
+        RoleUserAssignment = new_state.apps.get_model('dab_rbac', 'RoleUserAssignment')
+        assert RoleUserAssignment.objects.filter(user=user.id, object_id=org.id).exists()