Fix Slack integration leftovers after disconnecting (#2986)

# What this PR does

Improve Slack disconnect cleanup:
- Reset Slack user group for schedules
- Reset Slack user identity for deleted users

## Which issue(s) this PR fixes

https://github.com/grafana/oncall-private/issues/1962

## Checklist

- [x] Unit, integration, and e2e (if applicable) tests updated
- [x] Documentation added (or `pr:no public docs` PR label added if not
required)
- [x] `CHANGELOG.md` updated (or `pr:no changelog` PR label added if not
required)

CHANGELOG.md

@@ -19,6 +19,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Fixed
 
 - Don't update Slack user groups for deleted organizations by @vadimkerr ([#2985](https://github.com/grafana/oncall/pull/2985))
+- Fix Slack integration leftovers after disconnecting by @vadimkerr ([#2986](https://github.com/grafana/oncall/pull/2986))
 
 ## v1.3.35 (2023-09-05)
 

engine/apps/slack/tasks.py

@@ -162,17 +162,13 @@ def unpopulate_slack_user_identities(organization_pk, force=False, ts=None):
 
     organization = Organization.objects.get(pk=organization_pk)
 
-    users_to_update = []
-    for user in organization.users.filter(slack_user_identity__isnull=False):
-        user.slack_user_identity = None
-        users_to_update.append(user)
-
-    User.objects.bulk_update(users_to_update, ["slack_user_identity"], batch_size=5000)
+    # Reset slack_user_identity for organization users (make sure to include deleted users in the queryset)
+    User.objects.filter_with_deleted(organization=organization).update(slack_user_identity=None)
 
     if force:
         organization.slack_team_identity = None
         organization.general_log_channel_id = None
-        organization.save()
+        organization.save(update_fields=["slack_team_identity", "general_log_channel_id"])
 
 
 @shared_dedicated_queue_retry_task(autoretry_for=(Exception,), retry_backoff=True, max_retries=0)
@@ -626,12 +622,9 @@ def clean_slack_integration_leftovers(organization_id, *args, **kwargs):
     from apps.alerts.models import ChannelFilter
     from apps.schedules.models import OnCallSchedule
 
-    logger.info(f"Start clean slack leftovers for organization {organization_id}")
+    logger.info(f"Cleaning up for organization {organization_id}")
     ChannelFilter.objects.filter(alert_receive_channel__organization_id=organization_id).update(slack_channel_id=None)
-    logger.info(f"Cleaned ChannelFilters slack_channel_id for organization {organization_id}")
-    OnCallSchedule.objects.filter(organization_id=organization_id).update(channel=None)
-    logger.info(f"Cleaned OnCallSchedule slack_channel_id for organization {organization_id}")
-    logger.info(f"Finish clean slack leftovers for organization {organization_id}")
+    OnCallSchedule.objects.filter(organization_id=organization_id).update(channel=None, user_group=None)
 
 
 @shared_dedicated_queue_retry_task(autoretry_for=(Exception,), retry_backoff=True, max_retries=10)

engine/apps/slack/tests/test_reset_slack.py

@@ -8,6 +8,9 @@ from rest_framework.response import Response
 from rest_framework.test import APIClient
 
 from apps.api.permissions import LegacyAccessControlRole
+from apps.schedules.models import OnCallScheduleWeb
+from apps.slack.tasks import clean_slack_integration_leftovers, unpopulate_slack_user_identities
+from apps.user_management.models import User
 
 
 @pytest.mark.django_db
@@ -32,3 +35,58 @@ def test_reset_slack_integration_permissions(
         response = client.post(url, format="json", **make_user_auth_headers(user, token))
 
     assert response.status_code == expected_status
+
+
+@pytest.mark.django_db
+def test_clean_slack_integration_leftovers(
+    make_organization_with_slack_team_identity,
+    make_alert_receive_channel,
+    make_channel_filter,
+    make_slack_user_group,
+    make_schedule,
+):
+    organization, slack_team_identity = make_organization_with_slack_team_identity()
+
+    # create channel filter with Slack channel
+    alert_receive_channel = make_alert_receive_channel(organization)
+    channel_filter = make_channel_filter(alert_receive_channel, slack_channel_id="test")
+
+    # create schedule with Slack channel and user group
+    user_group = make_slack_user_group(slack_team_identity)
+    schedule = make_schedule(organization, schedule_class=OnCallScheduleWeb, channel="test", user_group=user_group)
+
+    # clean Slack integration leftovers
+    clean_slack_integration_leftovers(organization.pk)
+    channel_filter.refresh_from_db()
+    schedule.refresh_from_db()
+
+    # check that references to Slack objects are removed
+    assert channel_filter.slack_channel_id is None
+    assert schedule.channel is None
+    assert schedule.user_group is None
+
+
+@pytest.mark.django_db
+def test_unpopulate_slack_user_identities(
+    make_organization_and_user_with_slack_identities, make_user_with_slack_user_identity
+):
+    # create organization and user with Slack connected
+    organization, user, slack_team_identity, _ = make_organization_and_user_with_slack_identities()
+
+    # create & delete user with Slack connected
+    deleted_user, _ = make_user_with_slack_user_identity(slack_team_identity, organization)
+    User.objects.filter(pk=deleted_user.pk).delete()
+
+    # unpopulate Slack user identities
+    unpopulate_slack_user_identities(organization.pk, force=True)
+    user.refresh_from_db()
+    deleted_user.refresh_from_db()
+    organization.refresh_from_db()
+
+    # check that references to Slack user identities are removed
+    assert user.slack_user_identity is None
+    assert deleted_user.slack_user_identity is None
+
+    # check that Slack specific info is reset for organization
+    assert organization.slack_team_identity is None
+    assert organization.general_log_channel_id is None