# What this PR does
This PR adds support for routing alerts based on labels.
https://www.loom.com/share/4401de6e3c4945d5b8961fe43ee373c9
Additionally:
- improve the typing around the `get_object` method that is inherited by
[`PublicPrimaryKeyMixin.get_object`](https://github.com/grafana/oncall/blob/dev/engine/common/api_helpers/mixins.py#L153)
in most of our models. `PublicPrimaryKeyMixin` is generic, so it can be
more strongly typed when it is being subclassed, which results in better
typing of the `get_object` method in child classes
- I decided to do this because I started looking into this task via the
[`AlertReceiveChannelView.send_demo_alert`
method/endpoint](https://github.com/grafana/oncall/blob/dev/engine/apps/api/views/alert_receive_channel.py#L242).
Within that method, `instance` is not typed because the inherited
`get_object` method is not typed.. I digress 😄
- improve typing around `Alert.create` and
`apps.integrations.tasks.create_alert` functions
- make `Alert.render_group_data` more DRY by extracting some logic out
into `Alert._apply_jinja_template_to_alert_payload_and_labels`
- deduplicate the logic of `value.strip().lower() in ["1", "true",
"ok"]` into a shared function,
`common.jinja_templater.apply_jinja_template.templated_value_is_truthy`
Closes https://github.com/grafana/oncall-private/issues/2490
## Checklist
- [x] Unit, integration, and e2e (if applicable) tests updated
- [x] `CHANGELOG.md` updated (or `pr:no changelog` PR label added if not
required)
- [x] Documentation added (or `pr:no public docs` PR label added if not
required) (will be done in #3762)
