feat: management command to truncate social auth (#2376)

truncates all entries in this table were modified outside of the last 90
days. Doesn't take any arguments because YAGNI; can easily be modified
in the future if the situation changes.

FIXES: APER-3160

credentials/apps/core/management/commands/tests/test_truncate_social_auth.py

@@ -0,0 +1,45 @@
+"""
+Tests for the truncate_social_auth management command
+"""
+
+from datetime import datetime, timedelta, timezone
+from unittest.mock import patch
+
+from django.contrib.auth import get_user_model
+from django.core.management import call_command
+from django.test import TestCase
+from social_django.models import UserSocialAuth
+
+from credentials.apps.core.tests.factories import UserFactory, UserSocialAuthFactory
+
+
+User = get_user_model()
+
+JSON = "application/json"
+
+
+class TruncateUserSocialAuthTest(TestCase):
+    def setUp(self):
+        """Create social auth records for test"""
+        super().setUp()
+        now = datetime.now(timezone.utc)
+        long_ago = now - timedelta(days=180)
+
+        self.user_young = UserFactory()
+        self.user_old = UserFactory()
+
+        self.auth_young = UserSocialAuthFactory(user_id=self.user_young.id, modified=now)
+        with patch("django.utils.timezone.now") as mock_now:
+            mock_now.return_value = long_ago
+            self.auth_old = UserSocialAuthFactory(user_id=self.user_old.id, modified=long_ago)
+
+    def test_delete_old_rows(self):
+        """verify that only old auth records are deleted."""
+        auth_records = UserSocialAuth.objects.all()
+        self.assertEqual(len(auth_records), 2)
+
+        call_command("truncate_social_auth")
+
+        auth_records = UserSocialAuth.objects.all()
+        self.assertEqual(len(auth_records), 1)
+        self.assertEqual(auth_records[0], self.auth_young)

credentials/apps/core/management/commands/truncate_social_auth.py

@@ -0,0 +1,38 @@
+"""
+Django managment command to truncate the social_auth_usersocialauth table.
+
+The social-auth-app-django plugin can have migrations on upgrade, and those
+migrations can fail when the social_auth_usersocialauth table is too large.
+It's safe to truncate the table; it doesn't affect logged in users at all.
+However, to avoid any risk, this keeps a window of learners who have logged
+in in the last 90 days.
+"""
+
+import logging
+from datetime import datetime, timedelta, timezone
+
+from django.contrib.auth import get_user_model
+from django.core.management.base import BaseCommand
+from social_django.models import UserSocialAuth
+
+
+logger = logging.getLogger(__name__)
+User = get_user_model()
+
+
+class Command(BaseCommand):
+    def handle(self, *args, **options):
+        """Truncate the social_auth_usersocialauth table."""
+        now = datetime.now(timezone.utc)
+        error_message = "truncate_social_auth deleted failed"
+        # This is unlikely to be a run-more-than-once management command.
+        # If the need rearises, this timedelta could become an argument.
+        window_to_keep = timedelta(days=90)
+        try:
+            deleted = UserSocialAuth.objects.filter(modified__lte=now - window_to_keep).delete()
+        except:  # pylint: disable=bare-except
+            logger.exception(error_message)
+        try:
+            logger.info(f"truncate_social_auth deleted {deleted[0]} rows")
+        except IndexError:
+            logger.error(error_message)

credentials/apps/core/tests/factories.py

@@ -4,6 +4,7 @@
 
 from django.contrib.sites.models import Site
 from factory import Faker, PostGenerationMethodCall, Sequence, SubFactory, django, sequence
+from social_django.models import UserSocialAuth
 
 from credentials.apps.core.models import SiteConfiguration, User
 
@@ -56,3 +57,12 @@ class Meta:
     certificate_help_url = Faker("url")
     records_help_url = Faker("url")
     twitter_username = Faker("word")
+
+
+class UserSocialAuthFactory(django.DjangoModelFactory):
+    class Meta:
+        model = UserSocialAuth
+
+    user_id = Faker("random_int")
+    provider = Faker("word")
+    extra_data = Faker("json")