Concrète Mixer internet radio Docker image

This repo contains files for a Docker image that runs:

• Concrète Mixer - an ambient sound file mixing audio app
• Darkice
• Icecast

The image is intended to run on a Raspberry Pi to provide a closet-based internet radio station.

Prerequisites

A Raspberry Pi, preferably a model 3, preferably running Raspbian (though I think any Linux with systemd should be fine), definitely running Docker. An internet connection is also a must.

Installation

Install snd-aloop module

The Docker container makes use of the ALSA snd-aloop module. Concrete Mixer directs sends its output to device Loopback,0 while Darkice listens for the output on Loopback,1. To set up snd-aloop to load on boot, run:

sudo -i
echo snd-aloop >> /etc/modules
reboot

When the pi reboots, run aplay -l and in the sound hardware components listed you should see:

card 0: Loopback [Loopback], device 0: Loopback PCM [Loopback PCM]
  Subdevices: 8/8
  ...
card 0: Loopback [Loopback], device 1: Loopback PCM [Loopback PCM]
  Subdevices: 8/8
  ...

Installing the docker image

With Docker installed on your pi, run:

docker run -d --device=/dev/snd:/dev/snd -p 8000:8000 concretemixer/cm-rpi-internet:latest

Docker will download the image from dockerhub and build and run a new container.

All going well, at the end of the process you should hear Concrète Mixer playing on http://{your Pi's ip address}:8000/concrete-mixer.mp3.

Setting the docker container to load on boot

To do this:

1. Copy the contents of this file to /etc/systemd/system/docker-concrete_mixer_internet.service:

2. Restart systemd so the new file is detected:

   systemctl daemon-reload

3. Enable the service:

   systemctl enable docker-concrete_mixer_internet.service

4. Reboot the pi, and the Concrète Mixer service should start automatically.

Security

The conf/icecast2.xml file provides a default username and password. If you ever expose your Pi to the internet you should fork this repo, and specify secure credentials in conf/icecast2.xml and conf/darkice.cfg.

See also

An Concrète Mixer docker image that outputs audio thru the Pi's sound card