Reconstitute migration file

Do the things as a proper 3-step process -- add new stuff, copy the data, drop the old.

awx/main/migrations/0189_inbound_hop_nodes.py

@@ -1,39 +1,36 @@
-# Generated by Django 4.2.6 on 2024-01-19 03:13
+# Generated by Django 4.2.6 on 2024-01-19 19:24
 
 import django.core.validators
 from django.db import migrations, models
 import django.db.models.deletion
 
 
-def create_receptor_address(apps, schema_editor):
+def create_receptor_addresses(apps, schema_editor):
     """
-    if listener_port was defined on an instance, create a receptor address for it
+    If listener_port was defined on an instance, create a receptor address for it
     """
     Instance = apps.get_model('main', 'Instance')
     ReceptorAddress = apps.get_model('main', 'ReceptorAddress')
-    for instance in Instance.objects.all():
-        if instance.listener_port:
-            instance.peers_from.all()
-            ReceptorAddress.objects.create(
-                instance=instance,
-                address=instance.hostname,
-                port=instance.listener_port,
-                peers_from_control_nodes=instance.peers_from_control_nodes,
-                protocol='tcp',
-                is_internal=False,
-                canonical=True,
-            )
+    for instance in Instance.objects.exclude(listener_port=None):
+        ReceptorAddress.objects.create(
+            instance=instance,
+            address=instance.hostname,
+            port=instance.listener_port,
+            peers_from_control_nodes=instance.peers_from_control_nodes,
+            protocol='tcp',
+            is_internal=False,
+            canonical=True,
+        )
 
 
-def link_to_receptor_address(apps, schema_editor):
+def link_to_receptor_addresses(apps, schema_editor):
     """
-    modify each InstanceLink to point to the newly created
-    ReceptorAddresses, through the target_new field
-    target_new will be renamed to target in an operation below
+    Modify each InstanceLink to point to the newly created
+    ReceptorAddresses, using the new target field
     """
     InstanceLink = apps.get_model('main', 'InstanceLink')
     for link in InstanceLink.objects.all():
-        link.target_new = link.target.receptor_addresses.get()
+        link.target = link.target_old.receptor_addresses.get()
         link.save()
 
 
@@ -78,6 +75,11 @@ class Migration(migrations.Migration):
             model_name='instancelink',
             name='source_and_target_can_not_be_equal',
         ),
+        migrations.RenameField(
+            model_name='instancelink',
+            old_name='target',
+            new_name='target_old',
+        ),
         migrations.AlterUniqueTogether(
             name='instancelink',
             unique_together=set(),
@@ -87,9 +89,10 @@ class Migration(migrations.Migration):
             name='managed',
             field=models.BooleanField(default=False, editable=False, help_text='If True, this instance is managed by the control plane.'),
         ),
-        migrations.AddConstraint(
+        migrations.AlterField(
             model_name='instancelink',
-            constraint=models.UniqueConstraint(fields=('source', 'target'), name='source_target_unique_together'),
+            name='source',
+            field=models.ForeignKey(help_text='The source instance of this peer link.', on_delete=django.db.models.deletion.CASCADE, to='main.instance'),
         ),
         migrations.AddField(
             model_name='receptoraddress',
@@ -101,46 +104,34 @@ class Migration(migrations.Migration):
             name='receptor_address',
             field=models.ManyToManyField(blank=True, to='main.receptoraddress'),
         ),
-        migrations.AddField(
-            model_name='instancelink',
-            name='target_new',
-            field=models.ForeignKey(
-                help_text='The target receptor address of this peer link.', null=True, on_delete=django.db.models.deletion.CASCADE, to='main.receptoraddress'
-            ),
-        ),
         migrations.AddConstraint(
             model_name='receptoraddress',
             constraint=models.UniqueConstraint(fields=('address',), name='unique_receptor_address', violation_error_message='Receptor address must be unique.'),
         ),
-        migrations.RunPython(create_receptor_address),
-        migrations.RunPython(link_to_receptor_address),
-        migrations.RemoveField(
-            model_name='instancelink',
-            name='target_new',
-        ),
-        migrations.AlterField(
-            model_name='instance',
-            name='peers',
-            field=models.ManyToManyField(related_name='peers_from', through='main.InstanceLink', to='main.receptoraddress'),
-        ),
-        migrations.AlterField(
+        migrations.AddField(
             model_name='instancelink',
             name='target',
             field=models.ForeignKey(
-                help_text='The target receptor address of this peer link.', on_delete=django.db.models.deletion.CASCADE, to='main.receptoraddress'
+                help_text='The target receptor address of this peer link.', null=True, on_delete=django.db.models.deletion.CASCADE, to='main.receptoraddress'
             ),
         ),
-        migrations.AlterField(
-            model_name='instancelink',
-            name='source',
-            field=models.ForeignKey(help_text='The source instance of this peer link.', on_delete=django.db.models.deletion.CASCADE, to='main.instance'),
+        migrations.RunPython(create_receptor_addresses),
+        migrations.RunPython(link_to_receptor_addresses),
+        migrations.RemoveField(
+            model_name='instance',
+            name='peers_from_control_nodes',
         ),
         migrations.RemoveField(
             model_name='instance',
             name='listener_port',
         ),
         migrations.RemoveField(
+            model_name='instancelink',
+            name='target_old',
+        ),
+        migrations.AlterField(
             model_name='instance',
-            name='peers_from_control_nodes',
+            name='peers',
+            field=models.ManyToManyField(related_name='peers_from', through='main.InstanceLink', to='main.receptoraddress'),
         ),
     ]

awx/main/models/ha.py

@@ -67,10 +67,9 @@ def has_policy_changes(self):
 class InstanceLink(BaseModel):
     class Meta:
         ordering = ("id",)
-        constraints = [models.UniqueConstraint(fields=['source', 'target'], name='source_target_unique_together')]
 
     source = models.ForeignKey('Instance', on_delete=models.CASCADE, help_text=_("The source instance of this peer link."))
-    target = models.ForeignKey('ReceptorAddress', on_delete=models.CASCADE, help_text=_("The target receptor address of this peer link."))
+    target = models.ForeignKey('ReceptorAddress', null=True, on_delete=models.CASCADE, help_text=_("The target receptor address of this peer link."))
 
     class States(models.TextChoices):
         ADDING = 'adding', _('Adding')