Is there any way to make a read-only sync folder like in Bittorrent Sync?
A friend of mine used to use BtSync to share his music folder with people. But BtSync is terrible and he switched to Syncthing. But there is no such feature in Syncthing.
Is a read-only sync folder planned to be implemented?
There already is a read only feature.
But it is different from the implementation in BTSync, but should be appropriate for your need.
Inside the folder settings you can activate “Master Folder”. It is documented here: http://docs.syncthing.net/users/foldermaster.html
While this setting is active, Syncthing will ignore every change made by other nodes.
This type of read-only folder would be nice to have. Also since the master could put a lot of data and slaves can do nothing to remove it there could be option to limit folder size for synching (with appropriate error message if limit reached).
I read somewhere, that there may be a "don’t send changes"
setting in the works (can’t find it anymore), which would make that node “read-only”. But this setting needs to be done on the read-only node, not on the master, so it is not applicable for non-trusted nodes.