Add unique embed_key to List model

bookwyrm/migrations/0120_list_embed_key.py

@@ -0,0 +1,29 @@
+# Generated by Django 3.2.5 on 2021-12-04 10:55
+
+from django.db import migrations, models
+import uuid
+
+
+def gen_uuid(apps, schema_editor):
+    """sets an unique UUID for embed_key"""
+    book_lists = apps.get_model("bookwyrm", "List")
+    db_alias = schema_editor.connection.alias
+    for book_list in book_lists.objects.using(db_alias).all():
+        book_list.embed_key = uuid.uuid4()
+        book_list.save(broadcast=False)
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("bookwyrm", "0119_user_feed_status_types"),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name="list",
+            name="embed_key",
+            field=models.UUIDField(editable=False, null=True, unique=True),
+        ),
+        migrations.RunPython(gen_uuid, reverse_code=migrations.RunPython.noop),
+    ]