Is there a Way to Prevent some Calendars from Sync and have them only visible online in the WebGUI?
For files you have file access control, currently you can’t use this for calendars but this could be a nice idea for a feature request.
You could try to achieve this in your apache configuration. Caldav-Logins are shown in the log as authenticated users:
ip - username [02/Jan/2017:21:13:52 +0000] "GET ...
compared to the web access
ip - - [02/Jan/2017:21:14:46 +0000] "GET ...
then you could put some rule on the path /nextcloud/remote.php/dav/principals/*. Or you could the user agent strings to filter and only allow web browsers.
Thx for the suggestion, i will try this with Nginx, since i didn’t use Apache on a Raspberry Pi 2. Mainly this came up, since i use eM Client on Desktop. eM Client seems to have a Problem with the Birthday Calendar. This Calendar is readonly on all Clients i use, but if a Birthday Alarm fires up on eM Client and i close the Alarm Window, eM Client trys to sync this back to the Server, which fails. The next time eM Client is started, eM Clients trys to sync it again and the same game comes with every restart of eM Client. I think it is a Bug in eM Client and currently i have re-added all Calendars again, except the Birthday Calender as Workaround.