Ensure add_domain migration creates the default domain correctly

Also modify get_domain_pk to use raw SQL to avoid problems with running inside migrations

pulpcore/app/migrations/0101_add_domain.py

@@ -2,16 +2,12 @@
 
 from django.conf import settings
 from django.db import migrations, models
-import django.db.models.deletion
 import django_lifecycle.mixins
 import pulpcore.app.models.access_policy
 import pulpcore.app.models.fields
-import pulpcore.app.models.upload
-import pulpcore.app.util
 import uuid
 
 
-
 DEFAULT_DELETE_TRIGGER = """
 CREATE OR REPLACE FUNCTION protect_default() RETURNS TRIGGER as $protect_default$
   BEGIN
@@ -30,6 +26,18 @@
 DROP FUNCTION IF EXISTS protect_default();
 """
 
+
+def create_default_domain(apps, schema_editor):
+    Domain = apps.get_model('core', 'Domain')
+    try:
+        default_domain = Domain.objects.get(name="default")
+    except Domain.DoesNotExist:
+        default_domain = Domain(
+            name="default", storage_class=settings.STORAGES["default"]["BACKEND"]
+        )
+        default_domain.save(skip_hooks=True)
+
+
 class Migration(migrations.Migration):
 
     dependencies = [
@@ -58,4 +66,5 @@ class Migration(migrations.Migration):
             bases=(django_lifecycle.mixins.LifecycleModelMixin, models.Model, pulpcore.app.models.access_policy.AutoAddObjPermsMixin),
         ),
         migrations.RunSQL(DEFAULT_DELETE_TRIGGER, reverse_sql=REMOVE_DEFAULT_DELETE_TRIGGER),
+        migrations.RunPython(code=create_default_domain, reverse_code=migrations.RunPython.noop),
     ]

pulpcore/app/util.py

@@ -573,7 +573,7 @@ def set_current_user_lazy(user):
 
 def get_default_domain():
     global default_domain
-    # This can be run in a migration, and once after
+    # This will run in a post-migration hook
     if default_domain is None:
         try:
             Domain = models.Domain
@@ -595,7 +595,19 @@ def get_domain():
 
 
 def get_domain_pk():
-    return get_domain().pk
+    """
+    THIS CAN/WILL BE RAN IN MIGRATIONS. DO NOT USE ORM FOR IT MIGHT GENERATE INVALID SQL.
+    """
+    if domain := current_domain.get():
+        return domain.pk
+    # Same behavior as get_domain: use currently set domain, else assume default domain
+    if default_domain:
+        return default_domain.pk
+    # If we haven't cached the default_domain then use raw SQL to get its PK
+    with connection.cursor() as cursor:
+        cursor.execute("SELECT pulp_id FROM core_domain WHERE name = 'default'")
+        row = cursor.fetchone()
+        return row[0]
 
 
 def set_domain(new_domain):