Radicale
Radicale is a server designed to support the CalDav and CardDav protocols. It operates either as a standalone package using its own internal http server or can be integrated with an existing webserver.
Installation
The package creates the radicale user and service as per the Radical systemd instructions, along with the /var/lib/radicale/collections data folder, so you can just enable radicale.service.
Configuration
The easiest thing is to follow the instructions at the Radicale website.
The main configuration file is located at /etc/radicale/config
If this is setup on a remote / headless system, consider adding the hosts option to enable remote access to the built-in web interface.
Many of the configuration options can be changed on the command-line:
$ radicale --help
Authentication
By default, anyone can access the web interface and create address books or calendars, so authentication should be considered.
Authentication is controlled by /etc/radicale/users which can use Apache httpasswd formatted passwords (as well as plaintext & other options). If you are not planning to install Apache HTTP Server, you can just use an online htpasswd generator to generate the hashes.
Integration
Mail Servers
If you run a mail server the or IMAP authentication plugins may be useful. If you use radicale-dovecot-auth with UNIX sockets, create a radicale.service drop-in file with the following contents:
[Service] RestrictAddressFamilies= RestrictAddressFamilies=~AF_PACKET AF_NETLINK
This allows the process to open sockets.
Web Servers
Radicale provides its own web server (initially restricted to localhost only), but it can be integrated with HTTP webservers like Apache HTTP Server via Reverse Proxy or the WSGI interface.
Client support
Since it uses the CalDav and CardDav protocols, it should support most clients. Currently, the officially supported list is this.
The following list may or may not be accurate:
- Thunderbird Lightning extension and Cardbook
- GNOME/Evolution, Contacts and Calendar
- KOrganizer korganizer
- InfCloud , CalDavZAP, CardDavMATE
- syncEvolution
- aCal, ContactSync, CalendarSync, CalDAV-Sync CardDAV-Sync and DAVx⁵ for Android
- Mac OSX Calendar/Contacts
- Apple iOS
- Note that iOS requires a SSL in order to sync CalDAV/CarDAV (as of iOS14 self-signed SSL is sufficient for Radicale to integrate as an account) , this can be created by following the instructions in OpenSSL#Generate a self-signed certificate with private key in a single command.
Troubleshooting
DecSync plugin fails
If you use the plugin and it errors with install the package.