BaseChannelListener.listen() only called pubsub.unsubscribe() in its
finally block: the pubsub connection and the listener's own Redis client
were never released, leaking a connection for every install/uninstall
(_watcher) and every recreation of the app-status listener. The Celery
task notifiers were likewise never closed, and used the deprecated
Redis.close() instead of aclose().
- add aclose() to BaseChannelNotifier and BaseChannelListener
- listen() now closes the pubsub and its Redis client in finally
- close the notifiers in the app_manage / app_status_update tasks and
switch to aclose()
- back off in the app-status watch loop so a Redis outage no longer
spins, and drop a leftover debug print
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
This is a feature that allows to fetch the app status via a celery
task which stores the result in the Redis database and notifies the API
of the change. The API sends a notification to connected clients via the
SSE mechanism.
Using a background task allows to avoid crashing the whole API if the
script call fails.
The by default the cache is refreshed every 30 minutes. This can be
changed by setting the `BAPI_APP_STATUS_UPDATE_INTERVAL_MIN` environment
variable.
refs #123
