email-alert-api: Subscriber List Audit
Background
At the moment it's possible to get into a state where subscriber lists exist but cannot be triggered:
- if the keys or fields used to trigger the list are out-of-date with real content,
- if a format is fully retired without the correct manual intervention to clean up the lists,
- if content is unpublished and the automatic list cleanup code fails.
To determine whether untriggerable lists exist, we can run an audit over the gov.uk website using the sitemap. We iterate over the sitemap, getting the content item for each path and then comparing it against the EmailAlertCriteria (to check if the path would ever trigger a subscriber list), then if it passes that test against the ContentItemListQuery, which returns a list of SubscriberLists that would be triggered by major changes to that path. For each of those SubscriberLists, we update a last_audited_at field with the time the audit started. At the end of the process, any list that has an empty last_audited_at field or where the field is older than the time the audit started must not have been marked, so we know that it can't be triggered.
Running the audit
This is a long-running job which needs to be run asynchronously. To kick it off, use:
kubectl -n apps exec -it deploy/email-alert-api -- rake 'subscriber_list_audit:start'
NB: It will probably only reliably run in production, as the time taken to iterate over the sight may be more than a day, which in integration will be interrupted by the environment sync.
To check the number of workers remaining on the job:
kubectl -n apps exec -it deploy/email-alert-api -- rake 'subscriber_list_audit:queue_size'
When there are no workers remaining, you can run:
kubectl -n apps exec -it deploy/email-alert-api -- rake 'subscriber_list_audit:report[2024-04-16]'
to get a list of all subscriber lists that have either not been marked in an audit, or have not been marked in an audit since the specified date.