Automatically scan external changes for Nextcloud local storage.

Nextcloud uses a database to keep track of the files it stores. However, if a file is externally modified, the database won't know. It seems that the only possible way to inform the database is to run occ files:scan, which can be time- and resource-consuming if the whole storage is periodically scanned.

This Python script uses inotifywait to watch for changes and issues scan requests for the modified part on demand.

• Linux with systemd
• Nextcloud 14+ installation
• php and inotifywait in PATH
• Python 2.7 or 3.2+ as /usr/bin/python

The script should work if modified for other environments.

1. Clone this repo: git clone https://github.com/Blaok/nextcloud-inotifyscan; cd nextcloud-inotifyscan
2. Install the script and config in the correct locations: sudo make install
3. Figure out which Unix username is running Nextcloud; on Debian/Ubuntu this is usually www-data
4. Create /etc/nextcloud-inotifyscan/username.ini according to the example given in /etc/nextcloud-inotifyscan/sample.ini
5. Enable and start the service: sudo systemctl enable --now nextcloud-inotifyscan@username

• The data dir path is now read from /path/to/nextcloud/config.php automatically.
• Multiple users and multiple Nextcloud installation instances can be watched in a single service.
• Local filesystem folders added via the external storage app are supported.

• This script is tested on Ubuntu 18.04 LTS
  • To install inotifywait on Ubuntu, use sudo apt install inotify-tools
• This script ignores hidden files (inotifywait --exclude '/\.'), as Nextcloud does
• A similar project implemented in php, files_inotify, doesn't seem to work at this point in time exists but I'm not sure if it works
• Watching ~2000 directories with ~30000 files, inotifywait consumes less than 4MB memory (RES+SHR)
• To watch more than 8192 directories, fs.inotify.max_user_watches may need to be increased via sysctl
• Nextcloud 14+ is required for the --shallow flag