set default uuid

awx/main/managers.py

@@ -115,8 +115,6 @@ class InstanceManager(models.Manager):
         raise RuntimeError("No instance found with the current cluster host id")
 
     def register(self, uuid=None, hostname=None, ip_address=None, node_type='hybrid', defaults=None):
-        if not uuid:
-            uuid = str(uuid4())
         if not hostname:
             hostname = settings.CLUSTER_HOST_ID
         with advisory_lock('instance_registration_%s' % hostname):
@@ -149,7 +147,7 @@ class InstanceManager(models.Manager):
                     return (False, instance)
 
             # Create new instance, and fill in default values
-            create_defaults = dict(capacity=0, uuid=uuid)
+            create_defaults = dict(capacity=0)
             if defaults is not None:
                 create_defaults.update(defaults)
             if node_type == 'execution' and 'version' not in create_defaults:

awx/main/migrations/0154_set_default_uuid.py

@@ -0,0 +1,18 @@
+# Generated by Django 2.2.20 on 2021-09-01 22:53
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('main', '0153_instance_last_seen'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='instance',
+            name='uuid',
+            field=models.CharField(default='00000000-0000-0000-0000-000000000000', max_length=40),
+        ),
+    ]

awx/main/models/ha.py

@@ -59,7 +59,7 @@ class Instance(HasPolicyEditsMixin, BaseModel):
     objects = InstanceManager()
 
     # Fields set in instance registration
-    uuid = models.CharField(max_length=40)
+    uuid = models.CharField(max_length=40, default='00000000-0000-0000-0000-000000000000')
     hostname = models.CharField(max_length=250, unique=True)
     ip_address = models.CharField(
         blank=True,