Rediscovering CardDAV

I can no longer sync iOS’ Contacts with my macOS Catalina’s Finder; the OS insists I’ve iCloud configured for Contacts which I do not. I’ve gone through all the steps Apple recommends, done the upgrades and the reboots, but there’s nothing doing. All the swearing and threatening of moving to a different operating system aren’t really helping. This started sometime after I wrote about setting up macOS to “dial” a number using a shell script , but it cannot be related.

I was spilling my sorrows on Christoph who simply said he avoids all those issues by using CardDAV . I slapped my forehead: I’ve been using CalDAV for years, for synchronizing two calendars across devices: my own calendar across two Macs, an iPad, and an iPhone, and the family calendar across the family’s devices. How could I have forgotten about CardDAV ?

Baïkal has served us well for many years (the modification timestamp on the configuration reads August 2013). Before looking at using it for CardDAV I thought I’d put it on my little FreeBSD system in a BastilleBSD jail. The calendar migration was easy enough but produced a litre or two of adrenalin when I watched one calendar after the other disappear from iCal. Anyway, I got the data imported and our small family was back in sync.

I then created a Baïkal address book for myself, set up macOS and an iPhone to use that, and created a pseudo person’s entry on the Mac and another on iOS, and experimented a bit with how long it takes either side to sync, etc. As soon as I was satisfied I copy/pasted all contacts from macOS’ internal address book to its CardDAV store. When my contacts showed up on the iPhone, I knew I was half in business. After an additional backup I cleared out all the local contacts on the Mac.

Android

I recently had to purchase a new old phone for testing OwnTracks on Android and settled for a used Samsung Galaxy S8, a device which vastly exceeded my expectations. A really nice piece of kit, if only it weren’t for Android … #halfkidding

I went the whole hog and decided to see how well I could work with the S8 and purchased a copy of DAVx5 which is a really good and well thought-out bit of software. There’s an Open Source but I decided to pay for the software – developers must live off something other than applause and fresh air.

I can create, edit, and delete contacts on the S8 and DAVx5 will synchronize them back via CardDAV to my server. Just the way it ought to be.

CLI FreeBSD / Linux

I mostly use Mutt as an email client which means I want to be able to integrate whichever solution I come up with with these tools. A quick search led me to install vdirsyncer which enables me to synchronize my CardDAV server with a local directory of VCard files on the file system. If I change any of these files the utility can then synchronize the changes back to the server. (Source code: vdirsyncer .) The program’s configuration file reminds me of OfflineIMAP’s and its operating principles are similar: I configure a local and a remote store which are kept in sync.

$ export REQUESTS_CA_BUNDLE=mensCA.crt
$ vdirsyncer discover
$ vdirsyncer sync

Now that I have a set of VCard files in a directory, I can use khard , an address book for the Unix command line, which reads, creates, and modifies these files, and which can also be integrated with other programs , suitable for my use with Mutt .

$ khard new ..
$ khard edit ..

$ vdirsyncer -v WARNING sync
$ khard list jolie
Address book: jpm-ab
Index    Name           Phone                          Email
1        Jolie, Jane    work, pref: +49 555 6302547    work, pref: jane.jolie@example.org

$ khard show jolie
Name: Jane Jolie
Full name: Jane Jolie
Address book: jpm-ab
General:
    Birthday: 1969-07-10
    Nickname: jj
Phone
    work, pref: +49 555 6302547
E-Mail
    work, pref: jane.jolie@example.org
Private:
    OwnTracks: owntracks/jjolie/s8
Miscellaneous
    UID: 9245cfe6-256f-40d3-aabf-b3bab4601273
    Webpage:
        - _$!<HomePage>!$_: jj.example.org
    Note: Actress

Khard is just an example; any program able to read or manipulate VCard files would be suitable.

Thunderbird

Thunderbird isn’t a client I use, but if I moved to FreeBSD or one of its desktop siblings, I likely would (in addition to Mutt), so I thought I’d do you the favor and see how well it supports CardDAV. It doesn’t really, because it lacks built-in support for CardDAV , but I found TBsync which, with Dav-4-TbSync , allow me to synchronize my CardDAV and CalDAV stores to it. I tested this on FreeBSD , and it seems to work well enough at a first glance.

I can edit address book entries on Thunderbird and thanks to a builtin scheduler can automatically (or on-demand) synchronize changes back to the server. TbSync is open source and there’s a short getting started page.

The Coronavirus isolation and my speaking more with friends inspired this blog post. Thank you, Christoph, for the heads up.