Snapcast (Docker Image)

Note

The Snapcast version is now available as docker image tag: e.g. v0.31. If you want to use the version based on the git tag use tag-<TAG>

Snapcast Multiroom audio docker image w/ Snapweb files.

Based on linuxserver/docker-baseimage-alpine & snapcast. Also available at DockerHub

Should get used in conjunction with a player, that plays to a FIFO, like:

• https://github.com/sweisgerber/docker-mopidy
• or any other player.

Features Include:

• Snapserver w/ sane defaults
• Snapclient (optional, needs mounting of host audio devices into docker)
  • I prefer using the snapclient as host distribution package.
• snapweb management interface & browser audio playback
  • default on http://:1780m which include a browser snapclient player
• alsa
• librespot (for functioning as spotify target)
• shairport-sync (for functioning as airplay target)
• FIFO usage to stream the audio from players to the network
• Based on linuxserver/docker-baseimage-alpine
  • ... which allows use of linuxserver/docker-mods to add more pip & OS packages
  • Uses s6-overlay from base image
  • small footprint

docker-compose

I strongly advice to use docker-compose, as using a docker commandline is quite annoying with a complex setup. An example can get found in the repository. A more complex example together with mopidy can get found at mopiroom.

version: "3"
services:
  snapcast:
    image: docker.io/sweisgerber/snapcast:latest
    hostname: snapcast
    environment:
      - PUID=1000
      - PGID=1000 # set to audio group ID
      - TZ=Europe/Berlin
      - START_SNAPCLIENT=false # set to `true` for snapclient to start
      # --host: name or ip of compose service or dockerhost
      # --soundcard: <ID> from `snapclient -l` from inside the container
      # - SNAPCLIENT_OPTS=--host snapcast --soundcard <ID>
      #   => Don't use quotes for SNAPCLIENT_OPTS="" !
      # - HOST_AUDIO_GROUP=<AUDIO-GID> # set to GID of host audio group
      - START_AIRPLAY=false # set to 'true' to enable Airplay support via Shairport-sync
    restart: "unless-stopped"
    ports:
      - 1704:1704
      - 1705:1705
      - 1780:1780
    # devices:
      # - /dev/snd:/dev/snd # optional, only if you want to use snapclient
    volumes:
      - /<path>/<to>/<snapcast>/config/:/config/
      - /<path>/<to>/<snapcast>/data/:/data/
      # /audio should get used to place FIFOs for audio playback from mpd/mopidy/host/etc
      - /<path>/<to>/audio-fifos/:/audio/

Configuration

• https://github.com/badaix/snapcast/blob/master/doc/configuration.md

Configuration SnapClient

To enable snapclient:

• Forward device /dev/snd into the container, which should get used exclusively by snapclient. Or try a more sophisticated setup:
  • https://github.com/mviereck/x11docker/wiki/Container-sound:-ALSA-or-Pulseaudio
  • https://stackoverflow.com/questions/51859636/docker-sharing-dev-snd-on-multiple-containers-leads-to-device-or-resource-bu
• Configue START_SNAPCLIENT=true as environment variable.
• Configure SNAPCLIENT_OPTS as environment variable as needed, or leave empty to try defaults.
  • probably you will need to specify soundcard --soundcard, find out with snapclient --list

In any case, give the official documentation a read

Development

Local manual build example:

docker buildx build ./ -t local/snapcast:latest --build-arg SNAPCAST_RELEASE=0.34.0 --build-arg LIBRESPOT_RELEASE=0.8.0