fix(reconciliation): serialize compute sync and enforce UUID identity

instances/api/viewsets.py

@@ -285,26 +285,28 @@ class CreateInstanceViewSet(viewsets.ViewSet):
                     machine = "q35"
                     firmware["secure"] = "yes"
 
-            ret = conn.create_instance(
-                name=serializer.validated_data["name"],
-                memory=serializer.validated_data["memory"],
-                vcpu=serializer.validated_data["vcpu"],
-                vcpu_mode=serializer.validated_data["vcpu_mode"],
-                uuid=util.randomUUID(),
-                arch=arch,
-                machine=machine,
-                firmware=firmware,
-                volumes=volume_list,
-                networks=serializer.validated_data["networks"],
-                nwfilter=serializer.validated_data["nwfilter"],
-                graphics=serializer.validated_data["graphics"],
-                virtio=serializer.validated_data["virtio"],
-                listener_addr=serializer.validated_data["listener_addr"],
-                video=serializer.validated_data["video"],
-                console_pass=serializer.validated_data["console_pass"],
-                mac=serializer.validated_data["mac"],
-                qemu_ga=serializer.validated_data["qemu_ga"],
-            )
+            with utils.libvirt_compute_lock(compute):
+                ret = conn.create_instance(
+                    name=serializer.validated_data["name"],
+                    memory=serializer.validated_data["memory"],
+                    vcpu=serializer.validated_data["vcpu"],
+                    vcpu_mode=serializer.validated_data["vcpu_mode"],
+                    uuid=util.randomUUID(),
+                    arch=arch,
+                    machine=machine,
+                    firmware=firmware,
+                    volumes=volume_list,
+                    networks=serializer.validated_data["networks"],
+                    nwfilter=serializer.validated_data["nwfilter"],
+                    graphics=serializer.validated_data["graphics"],
+                    virtio=serializer.validated_data["virtio"],
+                    listener_addr=serializer.validated_data["listener_addr"],
+                    video=serializer.validated_data["video"],
+                    console_pass=serializer.validated_data["console_pass"],
+                    mac=serializer.validated_data["mac"],
+                    qemu_ga=serializer.validated_data["qemu_ga"],
+                )
+                utils.refresh_instance_database(compute)
             msg = f"Instance {serializer.validated_data['name']} is created"
             return Response({"status": msg})
         else:

instances/migrations/0012_instance_unique_compute_uuid.py

@@ -0,0 +1,94 @@
+# Generated by Django 4.2.30 on 2026-09-27 10:57
+
+from django.db import migrations, models
+
+
+def deduplicate_instances(apps, schema_editor):
+    Instance = apps.get_model('instances', 'Instance')
+    UserInstance = apps.get_model('accounts', 'UserInstance')
+    from django.db.models import Count, Q
+    import uuid as uuid_mod
+
+    # Assign distinct UUIDs to legacy/corrupt records with null, empty, or whitespace UUIDs
+    # so they are not treated as duplicates or collapsed together
+    empty_uuid_instances = Instance.objects.filter(
+        Q(uuid__isnull=True) | Q(uuid="") | Q(uuid__regex=r"^\s*$")
+    )
+    for inst in empty_uuid_instances:
+        inst.uuid = str(uuid_mod.uuid4())
+        inst.save(update_fields=['uuid'])
+
+    duplicates = (
+        Instance.objects.exclude(uuid__isnull=True).exclude(uuid="")
+        .values('compute_id', 'uuid')
+        .annotate(count=Count('id'))
+        .filter(count__gt=1)
+    )
+    for item in duplicates:
+        instances = list(Instance.objects.filter(
+            compute_id=item['compute_id'],
+            uuid=item['uuid']
+        ).order_by('-id'))
+        primary = instances[0]
+        # Preserve is_template and non-default drbd across duplicate rows
+        merged_is_template = any(getattr(inst, 'is_template', False) for inst in instances)
+        non_default_drbd = next((inst.drbd for inst in instances if inst.drbd and inst.drbd != 'None'), None)
+        updated = False
+        if primary.is_template != merged_is_template:
+            primary.is_template = merged_is_template
+            updated = True
+        if non_default_drbd and primary.drbd != non_default_drbd:
+            primary.drbd = non_default_drbd
+            updated = True
+        if updated:
+            primary.save()
+
+        for dup in instances[1:]:
+            # Reassign or merge UserInstance relationships
+            for ui in UserInstance.objects.filter(instance=dup):
+                existing = UserInstance.objects.filter(instance=primary, user=ui.user).first()
+                if not existing:
+                    ui.instance = primary
+                    ui.save()
+                else:
+                    # Merge permissions with logical OR so no stronger permission is lost
+                    updated = False
+                    if ui.is_change and not existing.is_change:
+                        existing.is_change = True
+                        updated = True
+                    if ui.is_delete and not existing.is_delete:
+                        existing.is_delete = True
+                        updated = True
+                    if ui.is_vnc and not existing.is_vnc:
+                        existing.is_vnc = True
+                        updated = True
+                    if updated:
+                        existing.save()
+                    ui.delete()
+            dup.delete()
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('instances', '0011_createinstance_migrateinstance'),
+        ('accounts', '0001_initial'),
+    ]
+
+    operations = [
+        migrations.RunPython(deduplicate_instances, migrations.RunPython.noop),
+        migrations.AlterField(
+            model_name='flavor',
+            name='id',
+            field=models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID'),
+        ),
+        migrations.AlterField(
+            model_name='instance',
+            name='id',
+            field=models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID'),
+        ),
+        migrations.AddConstraint(
+            model_name='instance',
+            constraint=models.UniqueConstraint(fields=('compute', 'uuid'), name='unique_compute_uuid'),
+        ),
+    ]

instances/models.py

@@ -32,6 +32,11 @@ class Instance(models.Model):
 
     objects = InstanceManager()
 
+    class Meta:
+        constraints = [
+            models.UniqueConstraint(fields=["compute", "uuid"], name="unique_compute_uuid")
+        ]
+
     def __str__(self):
         return f"{self.compute}/{self.name}"
 

instances/utils.py

@@ -4,7 +4,9 @@ import string
 
 from accounts.models import UserInstance, UserAttributes
 from appsettings.settings import app_settings
+from computes.utils import libvirt_compute_lock
 from django.conf import settings
+from django.db import transaction
 from django.utils.translation import gettext_lazy as _
 from vrtManager.connection import connection_manager
 from vrtManager.instance import wvmInstance, wvmInstances
@@ -124,45 +126,86 @@ def migrate_instance(
         return
     if new_compute == instance.compute:
         return
-    try:
-        conn_migrate = wvmInstances(
-            new_compute.hostname,
-            new_compute.login,
-            new_compute.password,
-            new_compute.type,
-        )
+    c1, c2 = (
+        (instance.compute, new_compute)
+        if instance.compute.id < new_compute.id
+        else (new_compute, instance.compute)
+    )
+    with libvirt_compute_lock(c1):
+        with libvirt_compute_lock(c2):
+            conn_migrate = None
+            try:
+                conn_migrate = wvmInstances(
+                    new_compute.hostname,
+                    new_compute.login,
+                    new_compute.password,
+                    new_compute.type,
+                )
 
-        autostart = instance.autostart
-        conn_migrate.moveto(
-            instance.proxy,
-            instance.name,
-            live,
-            unsafe,
-            xml_del,
-            offline,
-            autoconverge,
-            compress,
-            postcopy,
-        )
-    finally:
-        conn_migrate.close()
+                autostart = instance.autostart
+                conn_migrate.moveto(
+                    instance.proxy,
+                    instance.name,
+                    live,
+                    unsafe,
+                    xml_del,
+                    offline,
+                    autoconverge,
+                    compress,
+                    postcopy,
+                )
+            finally:
+                if conn_migrate is not None:
+                    conn_migrate.close()
 
-    try:
-        conn_new = wvmInstance(
-            new_compute.hostname,
-            new_compute.login,
-            new_compute.password,
-            new_compute.type,
-            instance.name,
-        )
+            conn_new = None
+            try:
+                conn_new = wvmInstance(
+                    new_compute.hostname,
+                    new_compute.login,
+                    new_compute.password,
+                    new_compute.type,
+                    instance.name,
+                )
 
-        if autostart:
-            conn_new.set_autostart(1)
-    finally:
-        conn_new.close()
+                if autostart:
+                    conn_new.set_autostart(1)
+            finally:
+                if conn_new is not None:
+                    conn_new.close()
 
-    instance.compute = new_compute
-    instance.save()
+            with transaction.atomic():
+                target_inst = Instance.objects.filter(
+                    compute=new_compute, uuid=instance.uuid
+                ).first()
+                if target_inst and target_inst.id != instance.id:
+                    for ui in UserInstance.objects.filter(instance=instance):
+                        existing_ui = UserInstance.objects.filter(
+                            instance=target_inst, user=ui.user
+                        ).first()
+                        if not existing_ui:
+                            ui.instance = target_inst
+                            ui.save()
+                        else:
+                            updated = False
+                            if ui.is_change and not existing_ui.is_change:
+                                existing_ui.is_change = True
+                                updated = True
+                            if ui.is_delete and not existing_ui.is_delete:
+                                existing_ui.is_delete = True
+                                updated = True
+                            if ui.is_vnc and not existing_ui.is_vnc:
+                                existing_ui.is_vnc = True
+                                updated = True
+                            if updated:
+                                existing_ui.save()
+                            ui.delete()
+                    instance.delete()
+                    instance.id = target_inst.id
+                    instance.compute = new_compute
+                else:
+                    instance.compute = new_compute
+                    instance.save()
 
 
 def refr(compute):