The RealmAuditLog object ID was stored in the event sent to the
deferred_work queue as a means to update the row's extra_data field.
The extra_data field then stores the location of the export.
The `queue_data` variable is an intermediate step that's unnecessary.
Instead, the values from the queue event are assigned dierectly.
Also, the `worker` variable is not worth an assignment as it is only
referenced a single time per test case.
A FileNotFound error was set as the side-effect of the do_export_realm
mock and the DeferredWorker was made to consume the event explicitly.
Previously, the mock of do_export_realm was producing spammy output
as a result of a FileNotFound error coming from the queue processing of
`do_write_stats_file_for_realm_export`.
A unique path was created using the `LOCAL_UPLOADS_DIR` backend, similar
to the code used in `LocalUploadBackend`. The exported tarball was
copied to the directory, and an nginx url was created to serve the file
publicly.
Tweaked by tabbott to output an actual URL.
An endpoint was created in zerver/views. Basic rate-limiting was
implemented using RealmAuditLog. The idea here is to simply log each
export event as a realm_exported event. The number of events
occurring in the time delta is checked to ensure that the weekly
limit is not exceeded.
The event is published to the 'deferred_work' queue processor to
prevent the export process from being killed after 60s.
Upon completion of the export the realm admin(s) are notified.
Wyatt Hoodes