!1108 Add the migration with UUID PK

This will DROP the current Membership table !

arkindex/users/migrations/0008_add_membership_constraints.py

-# Generated by Django 3.1.3 on 2020-11-24 13:30
-
-from django.db import migrations, models
-
-
-class Migration(migrations.Migration):
-
-    dependencies = [
-        ('users', '0007_user_display_name'),
-    ]
-
-    operations = [
-        migrations.AlterField(
-            model_name='membership',
-            name='level',
-            field=models.PositiveIntegerField(help_text='User privilege level.'),
-        ),
-        migrations.AlterUniqueTogether(
-            name='membership',
-            unique_together={('user', 'group')},
-        ),
-    ]

arkindex/users/migrations/0008_membership_uuid_and_validation.py

+# Generated by Django 3.1.3 on 2020-11-24 13:30
+
+import uuid
+
+import django
+from django.conf import settings
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('users', '0007_user_display_name'),
+    ]
+
+    operations = [
+        # Drop membership table and re-create it
+        migrations.DeleteModel(
+            name='Membership',
+        ),
+        migrations.RemoveField(
+            model_name='group',
+            name='users',
+        ),
+        migrations.CreateModel(
+            name='Membership',
+            fields=[
+                ('id', models.UUIDField(default=uuid.uuid4, editable=False, primary_key=True, serialize=False)),
+                ('level', models.PositiveIntegerField(help_text='User privilege level.', validators=[django.core.validators.MinValueValidator(1), django.core.validators.MaxValueValidator(100)])),
+                ('group', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='memberships', to='users.group')),
+                ('user', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='memberships', to=settings.AUTH_USER_MODEL)),
+            ],
+            options={
+                'unique_together': {('user', 'group')},
+            },
+        ),
+        migrations.AddField(
+            model_name='group',
+            name='users',
+            field=models.ManyToManyField(related_name='groups', through='users.Membership', to=settings.AUTH_USER_MODEL),
+        ),
+    ]

arkindex/users/models.py

 import uuid
 
 from django.contrib.auth.models import AbstractBaseUser
+from django.core.validators import MaxValueValidator, MinValueValidator
 from django.db import models
 from django_rq.queues import get_queue
 from django_rq.settings import QUEUES
@@ -97,9 +98,16 @@ class Group(models.Model):
 
 
 class Membership(models.Model):
+    id = models.UUIDField(default=uuid.uuid4, primary_key=True, editable=False)
     user = models.ForeignKey(User, on_delete=models.CASCADE, related_name='memberships')
     group = models.ForeignKey(Group, on_delete=models.CASCADE, related_name='memberships')
-    level = models.PositiveIntegerField(help_text='User privilege level.')
+    level = models.PositiveIntegerField(
+        help_text='User privilege level.',
+        validators=[
+            MinValueValidator(1),
+            MaxValueValidator(100)
+        ]
+    )
 
     class Meta:
         unique_together = (