Self-hosting a CalDAV service

One of the common uses of Google’s “free” services is the appointment calendar. Similar services are provided by other vendors, but as part of my effort to free myself from Big Tech, I decided to host a CalDAV service on my own Ubuntu 22.04 server. There are two parts to hosting CalDAV: a server and a web client.

Radicale

For a server, I chose to use Radicale. Attempting to install Radicale using the radicale package built into Ubuntu led to frustration in the configuration: I wasted a lot of time trying to get Apache to be happy with it. It was much simpler to use the instructions linked to above, which involves downloading the package using pip (the Python package manager), and manually creating a config file and a systemd service file. These steps are mostly documented well, but there were a few ambiguities that need clarification.

First, the storage-filesystem-folder setting in the config file should be the system-wide value: /var/lib/radicale/collections. Here are the full contents of my config file /etc/radicale/config:

[server]
# Bind all addresses
hosts = 0.0.0.0:5232, [::]:5232

[auth]
type = htpasswd
htpasswd_filename = /usr/local/apache/var/.htpasswd
htpasswd_encryption = md5

[storage]
filesystem_folder = /var/lib/radicale/collections

In this example, I used basic authentication to control access to Radicale. I had earlier created the .htpasswd file for use with other web pages, using the htpasswd command, and simply reused it for the Radicale server.

Then the appropriate changes need to be made to an Apache2 site configuration. My site uses Let’s Encrypt, so the config file that I needed to edit was /etc/apache2/sites-enabled/000-default-le-ssl.conf. In this file, I added the following lines to the VirtualHost section:

  RewriteEngine On
  RewriteRule ^/radicale$ /radicale/ [R,L]
  <Location "/radicale/">
      ProxyPass        http://localhost:5232/ retry=0 upgrade=websocket
      ProxyPassReverse http://localhost:5232/
      RequestHeader    set X-Script-Name /radicale
  </Location>

The instructions for creating a systemd system-wide service file are accurate. But you must enable and start the radicale systemd service before attempting to view the radicale web page. You can check that the service started correctly by viewing its web interface using w3m (or some other text-mode browser):

w3m http://localhost:5232

InfCloud

For a web client, I chose InfCloud. The installation instructions are slightly hard to read, so here’s what I did (all commands run as root):

Change to the /var/www directory, download the InfCloud zip file, and unpack it:

wget https://inf-it.com/open-source/download/InfCloud_0.13.1.zip
unzip InfCloud_0.13.1.zip

Change to the newly-created infcloud directory and use your favorite editor to edit config.js. Change the href value in globalNetworkCheckSettings to the root URL for Radicale. In my case, the config line looked like this:

        href: 'https://www.example.com/radicale/',

Then edit the same Apache site configuration file that you edited above, and add the following lines to the VirtualHost section:

  Alias /infcloud /var/www/infcloud
  <Directory "/var/www/infcloud">
      AuthType Basic
      AuthName "InfCloud"
      AuthUserFile /usr/local/apache/var/.htpasswd
      Require valid-user
  </Directory>

In this example, I used the same basic authentication file (.htpasswd) as in Radicale, described above.

Try it out

After all this is done, restart Apache:

systemctl restart apache2
systemctl status apache2

If the status looks good, you should be able to visit Radicale by going to this URL (of course, substituting your own site name for “example”):

https://www.example.com/radicale

Log in using the use name and password that you used when you first created the .htpasswd file. Then create a calendar and an addressbook; if you don’t do this, InfCloud may have trouble.

Now you should be able to log into InfCloud at this URL:

https://www.example.com/infcloud/

You will have to log in twice: once for Apache basic authentication, and once for the InfCloud login screen.

/var/lib/radicale/collections/collection-root/user/big-huge-number

systemctl restart apache2