Add nextcloud-exporter and scrape it with prometheus
https://github.com/xperimental/nextcloud-exporter
With this we would get metrics like
- nextcloud_up: Indicates if the metrics could be scraped by the exporter...
- nextcloud_free_space_bytes: Free disk space in data directory in bytes
- nextcloud_database_size_bytes: Size of database in bytes as reported from engine
- nextcloud_apps_updates_available_total: Number of apps that have available updates
- ...
Not urgent thought.