The Radicale Project is a complete CalDAV (calendar) and CardDAV (contact) server solution.

Calendars and address books are available for both local and remote access, possibly limited through authentication policies. They can be viewed and edited by calendar and contact clients on mobile phones or computers. radicale.org

This is my working setup on Linux Debian with the python uwsgi server and Nginx.
I could not get the database to work, so the backend is file based!

Install

apt-get install radicale uwsgi uwsgi-plugin-http uwsgi-plugin-python

/etc/radicale/config

[encoding]
request = utf-8
stock = utf-8


[auth]
type = IMAP
imap_hostname = localhost
imap_port = 143
imap_ssl = False

[rights]
type = from_file
file = /home/username/radicale/etc/rights

[storage]
filesystem_folder = /home/username/radicale/collections

[logging]
config = /home/username/radicale/etc/logging
#debug = True

/home/username/radicale/etc/logging

[loggers]
keys = root

[handlers]
keys = console,file

[formatters]
keys = simple,full

[logger_root]
level = DEBUG
handlers = file

[handler_console]
class = StreamHandler
level = DEBUG
args = (sys.stdout,)
formatter = simple

[handler_file]
class = FileHandler
args = ('/home/username/radicale/radicale.log',)
level = INFO
formatter = full

[formatter_simple]
format = %(message)s

[formatter_full]
format = %(asctime)s - %(levelname)s: %(message)s

nginx

server {
    listen         80;
    server_name    dav.example.com;
    rewrite        ^ https://$server_name$request_uri? permanent;
}

server {
    listen 443;
    server_name     dav.example.com;
    root            /home/username/radicale/;
    index           index.html index.htm;
    access_log      /home/username/www/log/radicale-access.log;
    error_log       /home/username/www/log/radicale-error.log;

    ssl on;
    ssl_certificate      /home/username/etc/ssl/dav.example.com.unified.crt;
    ssl_certificate_key  /home/username/etc/ssl/dav.example.com.key;

    add_header      X-Frame-Options deny;

    gzip_static            on;
    gzip_http_version      1.1;
    gzip_proxied           expired no-cache no-store private auth;
    gzip_disable           "MSIE [1-6]\.";
    gzip_vary              on;

    location / {
        include uwsgi_params;
        uwsgi_pass unix:///tmp/radicale.sock;
    }
}

/home/username/radicale/radicale.wsgi

#!/usr/bin/env python

import radicale

radicale.log.start()
application = radicale.Application()

/etc/uwsgi/apps-available/radicale.ini

[uwsgi]
uid = www-data
gid = www-data
socket = /tmp/radicale.sock
plugins = http, python
wsgi-file = /home/username/radicale/radicale.wsgi