Radicale

Radicale is a WebDAV/CardDAV server.

Add user:

 > useradd -d /data/daemons/radicale -m radicale

Create data folder:

 > mkdir /data/cardcal
 > chown radicale:radicale /data/cardcal

enable pip (see deemon)

run as user radicale:

 > pip install --upgrade radicale

then start it:

 > radicale --storage-filesystem-folder=/data/cardcal

Setup nginx reverse proxy:

radicale.conf

location /radicale/ { # The trailing / is important!
    proxy_pass        http://localhost:5232/; # The / is important!
    proxy_set_header  X-Script-Name /radicale;
    proxy_set_header  X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header  Host $http_host;
    proxy_pass_header Authorization;
    proxy_set_header     X-Remote-User $remote_user; # allow automatic authentication using proxy credentials
    client_body_timeout 600; # to prevent timeouts importing huge calendars or contacts lists
}

and restart nginx.

Now go with browser to http://server-ip/radicale and setup.