Running Roundcube in a Docker Container

The simplest method is to run the official image:

docker run -e ROUNDCUBEMAIL_DEFAULT_HOST=mail -e ROUNDCUBEMAIL_SMTP_SERVER=mail -p 8000:80 -d roundcube/roundcubemail

where mail should be replaced by your host name for the IMAP and SMTP server.

Tags and Variants

Roundcube comes in three different variants (apache, fpm and fpm-alpine) which are all built on top of official php images of the same variants.

The latest-* tags always contain the latest stable version of Roundcube Webmail with the latest version of the php base images available. For recent major versions of Roundcube we have tags like 1.3.x. Those are continuously updated with versions of the according release series and updates to the base images.

We also publish full version tags (e.g. 1.3.10) but these just represent the version and base image at the time of the release. These tags do not receive any updates.

Configuration/Environment Variables

The following env variables can be set to configure your Roundcube Docker instance:

ROUNDCUBEMAIL_DEFAULT_HOST - Hostname of the IMAP server to connect to. For encypted connections, prefix the host with tls:// (STARTTLS) or ssl:// (SSL/TLS).

ROUNDCUBEMAIL_DEFAULT_PORT - IMAP port number; defaults to 143

ROUNDCUBEMAIL_SMTP_SERVER - Hostname of the SMTP server to send mails. For encypted connections, prefix the host with tls:// (STARTTLS) or ssl:// (SSL/TLS).

ROUNDCUBEMAIL_SMTP_PORT - SMTP port number; defaults to 587

ROUNDCUBEMAIL_PLUGINS - List of built-in plugins to activate. Defaults to archive,zipdownload

ROUNDCUBEMAIL_SKIN - Configures the default theme. Defaults to larry

ROUNDCUBEMAIL_UPLOAD_MAX_FILESIZE - File upload size limit; defaults to 5M

ROUNDCUBEMAIL_SPELLCHECK_URI - Fully qualified URL to a Google XML spell check API like google-spell-pspell

ROUNDCUBEMAIL_ASPELL_DICTS - List of aspell dictionaries to install for spell checking (comma-separated, e.g. de,fr,pl).

By default, the image will use a local SQLite database for storing user account metadata. It'll be created inside the unnamed volume /var/roundcube/db and can be backed up from there. Please note that this option should not be used for production environments.

Connect to a Database

The recommended way to run Roundcube is connected to a MySQL database. Specify the following env variables to do so:

ROUNDCUBEMAIL_DB_TYPE - Database provider; currently supported: mysql, pgsql, sqlite

ROUNDCUBEMAIL_DB_HOST - Host (or Docker instance) name of the database service; defaults to mysql or postgres depending on linked containers.

ROUNDCUBEMAIL_DB_PORT - Port number of the database service; defaults to 3306 or 5432 depending on linked containers.

ROUNDCUBEMAIL_DB_USER - The database username for Roundcube; defaults to root on mysql

ROUNDCUBEMAIL_DB_PASSWORD - The password for the database connection

ROUNDCUBEMAIL_DB_NAME - The database name for Roundcube to use; defaults to roundcubemail

Before starting the container, please make sure that the supplied database exists and the given database user has privileges to create tables.

Run it with a link to the MySQL host and the username/password variables:

docker run --link=mysql:mysql -d roundcube/roundcubemail

Persistent data

The Roundcube containers do not store any data persistently by default. There are, however, some directories that could be mounted as volume or bind mount to share data between containers or to inject additional data into the container:

/var/www/html: Roundcube installation directory
This is the document root of Roundcube. Plugins and additional skins are stored here amongst the Roundcube sources. Share this directory when using the FPM variant and let a webserver container serve the static files from here.
/var/roundcube/config: Location for additonal config files
See the Advanced configuration section for details.
/var/roundcube/db: storage location of the SQLite database
Only needed if using ROUNDCUBEMAIL_DB_TYPE=sqlite to persist the Roundcube database.
/tmp/roundcube-temp: Roundcube's temp folder
Temp files like uploaded attachments or thumbnail images are stored here. Share this directory via a volume when running multiple replicas of the roundcube container.

Docker Secrets

When running the Roundcube container in a Docker Swarm, you can use Docker Secrets to share credentials accross all instances. The following secrets are currently supported by Roundcube:

roundcube_des_key: Unique and random key for encryption purposes
roundcube_db_user: Database connection username (mappend to ROUNDCUBEMAIL_DB_USER)
roundcube_db_password: Database connection password (mappend to ROUNDCUBEMAIL_DB_PASSWORD)

Advanced configuration

Apart from the above described environment variables, the Docker image also allows to add custom config files which are merged into Roundcube's default config. Therefore the image defines the path /var/roundcube/config where additional config files (*.php) are searched and included. Mount a local directory with your config files - check for valid PHP syntax - when starting the Docker container:

docker run -v ./config/:/var/roundcube/config/ -d roundcube/roundcubemail

Check the Roundcube Webmail wiki for a reference of Roundcube config options.

Customized PHP settings can be implemented by mounting a configuration file to /usr/local/etc/php/conf.d/zzz_roundcube-custom.ini. For example, it may be used to increase the PHP memory limit (memory_limit=128M).

Installing Roundcube Plugins

With the latest updates, the Roundcube images contain the Composer binary which is used to install plugins. You can add and activate plugins by executing composer require <package-name> inside a running Roundcube container:

$ docker exec -it roundcubemail composer require johndoh/contextmenu --update-no-dev

If you have mounted the container's volume /var/www/html the plugins installed persist on your host system. Otherwise they need to be (re-)installed every time you update or restart the Roundcube container.

Examples

A few example setups using docker-compose can be found in our Github repository.

Building a Docker image

Use the Dockerfile in this repository to build your own Docker image. It pulls the latest build of Roundcube Webmail from the Github download page and builds it on top of a php:7.4-apache Docker image.

Build it from one of the variants directories with

docker build -t roundcubemail .

You can also create your own Docker image by extending from this image.

For instance, you could extend this image to add composer and install requirements for builtin plugins or even external plugins:

FROM roundcube/roundcubemail:latest

RUN set -ex; \
    apt-get update; \
    apt-get install -y --no-install-recommends \
        git \
    ; \
    \
    composer \
        --working-dir=/usr/src/roundcubemail/ \
        --prefer-dist \
        --prefer-stable \
        --update-no-dev \
        --no-interaction \
        --optimize-autoloader \
        require \
            johndoh/contextmenu \
    ; \

regisb/roundcubemail-docker