Calendar Synchronization

How to setup CalDev server on PC to store calendars & contacts.

Install Radicale

Radicale is CalDAV (calendars, to-do lists) and CalDAV (contacts) server. Instructions for ArchLinux: ArchLinux wiki.

On ArchLinux the data is stored by default at /var/lib/radicale and the configuration file is /etc/radicale/config. The service is created system wide. I changed it to run it as a user, so I can keep the data in the home folder. For configurations with multiple users it’s better to leave it system wide.

Enable and run the service

If you want to keep it system wide, enable and run the service:

sudo systemctl enable radicale
sudo systemctl start radicale

If you want to run it as a user, follow the instructions from Radicale page: Linux with systemd as a user. Copy and modify config, rights, user files from /etc/radicale. To manage service:

# Enable the service
systemctl --user enable radicale
# Start the service
systemctl --user start radicale
# Check the status of the service
systemctl --user status radicale
# View all log messages
journalctl --user --unit radicale.service

Restrict access

Install apache-tools from AUR. Run htpasswd -c <usersfile> <username>. Provide password. Append generated line from usersfile to users file.

In the config file configure:

[auth]
type = htpasswd
htpasswd_filename = <path to users file>
# encryption method used in the htpasswd file
htpasswd_encryption = md5

Enable SSL

Generate certificate: openssl req -x509 -newkey rsa:4096 -keyout radicale.key.pem -out radicale.cert.pem -nodes -days 99999. Use host name (eg. 192.168.0.20 as Common Name. Copy files to /etc/ssl folder in the case of system wide installation (in the case of user installation it can be ~/.config/radicale folder). In the case of system wide installation restrict key file access to radicale user (cert can be read by all).

Such generated certificate is still not perfect - Firefox complains, but we can live with it (DAVx5 on Android and Akonadi on Linux both work with it).

Add certificate to trusted. On ArchLinux:

sudo trust anchor /etc/ssl/radicale.cert.pem
sudo update-ca-trust

In the config file configure:

[server]
hosts = 0.0.0.0:5232
ssl = True
certificate = /etc/ssl/radicale.cert.pem
key = /etc/ssl/radicale.key.pem

Access radicale URL and add some calendars

Default URL: https://localhost:5232