Roundcube: Install CardDAV Plugin on Ubuntu 20.04

How to install the RCMCardDAV Plugin on Roundcube Webmail and and configure it for Nextcloud.

Install Packages

apt install roundcube roundcube-core roundcube-mysql roundcube-plugins roundcube-plugins-extra

Root Directory

The Roundcube root directory is on Ubuntu

/var/lib/roundcube

Download Plugin

Log out of Roundcube before continuing. The plugin runs its database initialisation procedure only when a user logs in.

Download latest tgz from https://github.com/mstilkerich/rcmcarddav

cd /var/lib/roundcube/plugins

wget https://github.com/mstilkerich/rcmcarddav/releases/download/v4.0.4/carddav-v4.0.4.tgz
tar -xzvf carddav-v4.0.4.tgz

cd carddav

Composer

curl -sS https://getcomposer.org/installer | php
php composer.phar update && php composer.phar install

Create Configfile

cp config.inc.php.dist config.inc.php

Enable Plugin

vi /var/lib/roundcube/config/config.inc.php
// List of active plugins (in plugins/ directory)
// Debian: install roundcube-plugins first to have any
$config['plugins'] = array("carddav", ...
);

CardDAV plugin is now installed but not connected to Nextcloud.

Add to Nextcloud

Login to Roundcube and press Settings | Preferences | CardDAV, enter credentials and press Save.

Finished!