Backport workaround for adding RA cooldown

Original backport with migration already removed:
2f3b57b

This adds unique migration field and update the code to use it.
This will avoid conflicts with future fields.

Must be cleaned up on a future release with an idempotent remove migration.

pulpcore/app/migrations/0118_remoteartifact_failed_at_backport49.py

@@ -0,0 +1,18 @@
+# Generated by Django 4.2.17 on 2025-01-10 20:56
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('core', '0117_task_unblocked_at'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='remoteartifact',
+            name='failed_at_backport49',
+            field=models.DateTimeField(null=True),
+        ),
+    ]

pulpcore/app/models/content.py

@@ -703,6 +703,10 @@ class RemoteArtifact(BaseModel, QueryMixin):
         sha256 (models.CharField): The expected SHA-256 checksum of the file.
         sha384 (models.CharField): The expected SHA-384 checksum of the file.
         sha512 (models.CharField): The expected SHA-512 checksum of the file.
+        failed_at_backport49 (models.DateTimeField):
+            The datetime of last download attempt failure. Only for old branches to
+            avoid migration backport issues.
+
 
     Relations:
 
@@ -725,6 +729,7 @@ class RemoteArtifact(BaseModel, QueryMixin):
     content_artifact = models.ForeignKey(ContentArtifact, on_delete=models.CASCADE)
     remote = models.ForeignKey("Remote", on_delete=models.CASCADE)
     pulp_domain = models.ForeignKey("Domain", default=get_domain_pk, on_delete=models.PROTECT)
+    failed_at_backport49 = models.DateTimeField(null=True)
 
     objects = BulkCreateManager.from_queryset(RemoteArtifactQuerySet)()
 

pulpcore/content/handler.py

@@ -827,7 +827,7 @@ async def _stream_content_artifact(self, request, response, content_artifact):
         remote_artifacts = (
             content_artifact.remoteartifact_set.select_related("remote")
             .order_by_acs()
-            .exclude(failed_at__gte=timezone.now() - timedelta(seconds=protection_time))
+            .exclude(failed_at_backport49__gte=timezone.now() - timedelta(seconds=protection_time))
         )
         async for remote_artifact in remote_artifacts:
             try:
@@ -1126,7 +1126,7 @@ async def finalize():
         try:
             download_result = await downloader.run()
         except DigestValidationError:
-            remote_artifact.failed_at = timezone.now()
+            remote_artifact.failed_at_backport49 = timezone.now()
             await remote_artifact.asave()
             await downloader.session.close()
             close_tcp_connection(request.transport._sock)