3c00345f54
# What this PR does Sometimes plugin sync fails with the following exception: ``` Cannot delete or update a parent row: a foreign key constraint fails (`schedules_oncallschedule`, CONSTRAINT `alerts_oncallschedul_team_id_4e633f4b_fk_user_mana` FOREIGN KEY (`team_id`) REFERENCES `user_management_team` (`id`))' ``` How to reproduce: 1. Create a new Grafana team 2. Create two schedules with different types (e.g. ICal and Web) and assign both schedules to the new team 3. Delete the team in Grafana 4. Trigger plugin sync, the sync will fail with the exception above This happens because the `OnCallSchedule` Django model is a polymorphic model and there's a [known bug](https://github.com/django-polymorphic/django-polymorphic/issues/229) in `django-polymorphic` with deleting related objects when using `SET_NULL` and `CASCADE`. This PR adds non-polymorphic versions of `SET_NULL` and `CASCADE` to use in schedule FKs as per this [comment](https://github.com/django-polymorphic/django-polymorphic/issues/229#issuecomment-398434412). This also applies to two other schedule FKs: `organization` and `user_group`, which are not working properly as well. ## 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)
38 lines
1.7 KiB
Python
38 lines
1.7 KiB
Python
import random
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from django.conf import settings
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from django.db import models
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def get_random_readonly_database_key_if_present_otherwise_default() -> str:
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"""
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This function returns a string, representing a key in the `DATABASES` django settings.
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If `settings.READONLY_DATABASES` is set, and non-empty, it randomly chooses one of the read-only databases,
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otherwise it falls back to "default".
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This is primarily intended to be used for django's `QuerySet.using()` function
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"""
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using_db = "default"
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if hasattr(settings, "READONLY_DATABASES") and len(settings.READONLY_DATABASES) > 0:
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using_db = random.choice(list(settings.READONLY_DATABASES.keys()))
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return using_db
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def NON_POLYMORPHIC_SET_NULL(collector, field, sub_objs, using):
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"""
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django-polymorphic has a bug where it doesn't properly handle the `on_delete` argument:
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https://github.com/django-polymorphic/django-polymorphic/issues/229#issuecomment-398434412.
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This is a workaround that uses the same code as the original `SET_NULL` function, but with the
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`non_polymorphic()` function applied to the `sub_objs` queryset.
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"""
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return models.SET_NULL(collector, field, sub_objs.non_polymorphic(), using)
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def NON_POLYMORPHIC_CASCADE(collector, field, sub_objs, using):
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"""
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django-polymorphic has a bug where it doesn't properly handle the `on_delete` argument:
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https://github.com/django-polymorphic/django-polymorphic/issues/229#issuecomment-398434412.
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This is a workaround that uses the same code as the original `CASCADE` function, but with the
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`non_polymorphic()` function applied to the `sub_objs` queryset.
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"""
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return models.CASCADE(collector, field, sub_objs.non_polymorphic(), using)
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