audio: add PipeWire+BT audio-bridge, mopidy (Qobuz+local), librespot (Spotify Connect)

- audio-bridge: alpine + pipewire + pipewire-pulse + wireplumber + bluez + dbus + tini
  Routes audio from librespot/mopidy/phone-BT to USB DAC (Q5K) via ALSA.
  Privileged + host network for bluetoothd HCI access.
- mopidy: built from python:3.12-slim-bookworm + pip (no ghcr.io dep).
  Qobuz (auth from developer.qobuz.com) + local files. PA bridge to audio-bridge.
- librespot: built from rust:1.85.1 on RPi (cross-compile too slow under qemu).
  Spotify Connect target named 'Klubhaus'. PA bridge to audio-bridge.

Both mopidy and librespot build locally to avoid ghcr.io auth/rate-limit issues.
PEQ stays on Q5K side (Qudelix app, 20 bands) for source-independent EQ.

infra/audio-bridge/Dockerfile

@@ -0,0 +1,26 @@
+# Audio bridge: PipeWire + PulseAudio bridge + BlueZ
+# Routes audio from librespot / mopidy / phone-Bluetooth to USB DAC (Qudelix 5K)
+# Cross-built for linux/arm64 on x86_64 build host via buildx + qemu.
+
+FROM alpine:3.20
+
+# PipeWire = audio router, handles ALSA sink + bluetooth A2DP sink + PA bridge.
+# wireplumber = PipeWire session manager (loads bluetooth modules on demand).
+# bluez = Bluetooth stack (needed for "bluetooth target" — phone → Pi audio).
+RUN apk add --no-cache \
+    pipewire \
+    pipewire-pulse \
+    wireplumber \
+    bluez \
+    alsa-utils \
+    alsa-plugins-pulse \
+    dbus \
+    tini
+
+COPY entrypoint.sh /entrypoint.sh
+RUN chmod +x /entrypoint.sh
+
+# D-Bus socket dir for bluetoothd / wireplumber / pipewire
+VOLUME ["/run/dbus", "/run/user/0"]
+
+ENTRYPOINT ["/sbin/tini", "--", "/entrypoint.sh"]

infra/audio-bridge/entrypoint.sh

@@ -0,0 +1,36 @@
+#!/bin/sh
+# audio-bridge entrypoint
+# Starts DBus, BlueZ, WirePlumber, then PipeWire. PA clients (librespot, mopidy)
+# connect via pipewire-pulse bridge on TCP localhost:4713.
+
+set -e
+
+mkdir -p /run/dbus /run/user/0
+chmod 0755 /run/dbus
+chmod 0700 /run/user/0
+
+# System DBus (needed by bluetoothd, wireplumber, pipewire)
+dbus-daemon --system --fork
+sleep 0.5
+
+# BlueZ (Bluetooth stack). --compat = legacy mode for older audio devices.
+# Disabled if no /dev/bluetooth/rfkill — wireplumber will skip BT modules.
+if [ -d /sys/class/bluetooth ]; then
+    bluetoothd --compat --nodetach &
+    sleep 0.5
+    echo "[audio-bridge] bluetoothd started"
+else
+    echo "[audio-bridge] no bluetooth hardware — skipping bluetoothd"
+fi
+
+# PipeWire runtime env
+export XDG_RUNTIME_DIR=/run/user/0
+export DBUS_SYSTEM_BUS_ADDRESS=unix:path=/run/dbus/system_bus_socket
+
+# WirePlumber first (it manages PipeWire session/policy, loads BT modules)
+wireplumber &
+sleep 1
+
+# PipeWire last. The pipewire-pulse package auto-loads the PA bridge module
+# so PA clients (librespot, mopidy) can connect via TCP localhost:4713.
+exec pipewire

infra/compose.yaml

@@ -78,4 +78,71 @@ services:
       FLASH_DURATION_SECONDS: "14"
       TZ: America/Los_Angeles
 
+  # Audio router: PipeWire + WirePlumber + PulseAudio bridge + BlueZ.
+  # Routes audio from librespot / mopidy / phone-Bluetooth to USB DAC (Q5K)
+  # via ALSA. Falls back to RPi 3.5mm / HDMI if no USB DAC.
+  # PEQ is applied on the DAC side (Q5K's Qudelix app, 20 bands), not here.
+  audio-bridge:
+    build: ./audio-bridge
+    container_name: audio-bridge
+    restart: unless-stopped
+    privileged: true
+    network_mode: host
+    devices:
+      - /dev/snd:/dev/snd
+    volumes:
+      - /run/dbus:/run/dbus                # system DBus (bluetoothd, wireplumber)
+      - /run/user/0:/run/user/0            # PipeWire runtime dir
+    cap_add:
+      - SYS_ADMIN                          # bluetoothd needs CAP_SYS_ADMIN for HCI
+      - NET_ADMIN
+
+  # Spotify Connect: phone's Spotify app shows "Klubhaus" as a Connect target.
+  # Outputs audio to audio-bridge via PulseAudio (localhost:4713).
+  # Built locally on RPi (cross-compile is too slow under qemu).
+  librespot:
+    build: ./librespot
+    image: infra-librespot:latest
+    container_name: librespot
+    restart: unless-stopped
+    depends_on:
+      - audio-bridge
+    network_mode: host
+    command: >
+      --name "Klubhaus"
+      --backend pulseaudio
+      --bitrate 320
+      --initial-volume 100
+      --enable-audio-cache
+      --cache /var/cache/librespot
+    volumes:
+      - librespot_cache:/var/cache/librespot
+
+  # Mopidy: Qobuz + local files + internet radio. Web UI on http://rpi:6680.
+  # Outputs audio to audio-bridge via PulseAudio (localhost:4713).
+  # Get Qobuz app_id + secret from https://developer.qobuz.com/api/v1/oauth
+  # Built locally from python:3.12-slim + pip install (no ghcr.io image).
+  mopidy:
+    build: ./mopidy
+    image: infra-mopidy:latest
+    container_name: mopidy
+    restart: unless-stopped
+    depends_on:
+      - audio-bridge
+    network_mode: host
+    ports:
+      - "6680:6680"
+    volumes:
+      - ./mopidy/data:/var/lib/mopidy
+      - ./mopidy/music:/music              # drop FLACs in infra/mopidy/music/
+    environment:
+      TZ: America/Los_Angeles
+      QOBUZ_APP_ID: "${QOBUZ_APP_ID:-}"
+      QOBUZ_APP_SECRET: "${QOBUZ_APP_SECRET:-}"
+      QOBUZ_USERNAME: "${QOBUZ_USERNAME:-}"
+      QOBUZ_PASSWORD: "${QOBUZ_PASSWORD:-}"
+
+volumes:
+  librespot_cache:
+
 

infra/librespot/Dockerfile

@@ -0,0 +1,51 @@
+# Librespot (Spotify Connect) for ARM64
+# Multi-stage: cross-compile Rust app on x86_64 builder, ship slim runtime.
+# Audio output: PulseAudio (connect to audio-bridge via TCP localhost:4713).
+
+FROM rust:1.85.1-bookworm AS builder
+
+# Cross-compile toolchain for aarch64
+RUN rustup target add aarch64-unknown-linux-gnu
+RUN dpkg --add-architecture arm64 \
+ && apt-get update \
+ && apt-get install -y --no-install-recommends \
+      gcc-aarch64-linux-gnu \
+      libpulse-dev:arm64 \
+      libasound2-dev:arm64 \
+      libssl-dev:arm64 \
+ && rm -rf /var/lib/apt/lists/*
+
+# Build librespot. Pin to a known tag.
+ARG LIBRESPOT_VERSION=v0.8.0
+RUN git clone --depth 1 --branch ${LIBRESPOT_VERSION} \
+        https://github.com/librespot-org/librespot.git /src
+WORKDIR /src
+ENV CARGO_TARGET_AARCH64_UNKNOWN_LINUX_GNU_LINKER=aarch64-linux-gnu-gcc
+RUN cargo build --release --target aarch64-unknown-linux-gnu --no-default-features --features="pulseaudio-backend"
+
+FROM debian:bookworm-slim
+
+RUN dpkg --add-architecture arm64 \
+ && apt-get update \
+ && apt-get install -y --no-install-recommends \
+      ca-certificates \
+      libpulse0:arm64 \
+      libasound2:arm64 \
+      libssl3:arm64 \
+ && rm -rf /var/lib/apt/lists/*
+
+COPY --from=builder /src/target/aarch64-unknown-linux-gnu/release/librespot /usr/local/bin/librespot
+
+# Cache dir for Spotify credentials
+VOLUME ["/var/cache/librespot"]
+
+# PulseAudio bridge is at localhost:4713 (audio-bridge)
+ENV PULSE_SERVER=tcp:127.0.0.1:4713
+
+CMD ["librespot", \
+     "--name", "Klubhaus", \
+     "--backend", "pulseaudio", \
+     "--device", "alsa_output.default", \
+     "--bitrate", "320", \
+     "--enable-audio-cache", \
+     "--cache", "/var/cache/librespot"]

infra/mopidy/Dockerfile

@@ -0,0 +1,32 @@
+# Mopidy music server with Qobuz + local files
+# Builds from python:3.12-slim + pip (no ghcr.io dependency)
+
+FROM python:3.12-slim-bookworm
+
+# System deps for mopidy + extensions + GStreamer playback
+RUN apt-get update \
+ && apt-get install -y --no-install-recommends \
+      gstreamer1.0-tools \
+      gstreamer1.0-plugins-good \
+      gstreamer1.0-plugins-bad \
+      libcairo2 \
+      libpango-1.0-0 \
+      libpangoft2-1.0-0 \
+      libgirepository1.0-dev \
+ && rm -rf /var/lib/apt/lists/*
+
+RUN pip install --no-cache-dir \
+    Mopidy==3.4.2 \
+    Mopidy-Qobuz \
+    Mopidy-Local
+
+# Default config (overridable via bind mount)
+COPY mopidy.conf /config/mopidy.conf
+
+VOLUME ["/var/lib/mopidy", "/music"]
+EXPOSE 6680
+
+# Run as the unprivileged "mopidy" user from python base
+USER nobody
+
+CMD ["mopidy", "--config", "/config/mopidy.conf"]

infra/mopidy/mopidy.conf

@@ -0,0 +1,38 @@
+[core]
+cache_dir = /var/lib/mopidy/cache
+config_dir = /config
+data_dir = /var/lib/mopidy/data
+max_tracklist_length = 10000
+
+[logging]
+verbosity = info
+format = %(levelname)-8s [%(name)s] %(message)s
+
+# Audio output → PipeWire (via PulseAudio bridge on TCP localhost:4713).
+# PipeWire handles routing to Q5K (USB) or fallback to RPi 3.5mm/HDMI.
+[audio]
+output = pulsesink server=127.0.0.1 name=mopidy
+mixer_volume = 100
+buffer_time = 1000
+
+[http]
+enabled = true
+hostname = 0.0.0.0
+port = 6680
+zeroconf = Klubhaus Mopidy
+
+# Qobuz streaming. Fill in credentials via env vars (set in compose.yaml):
+#   QOBUZ_APP_ID, QOBUZ_APP_SECRET, QOBUZ_USERNAME, QOBUZ_PASSWORD
+[qobuz]
+enabled = true
+app_id = ${QOBUZ_APP_ID}
+app_secret = ${QOBUZ_APP_SECRET}
+username = ${QOBUZ_USERNAME}
+password = ${QOBUZ_PASSWORD}
+
+# Local music files (mount /music in compose)
+[local]
+enabled = true
+media_dirs = /music
+scan_timeout = 5000
+playlists_dir = /var/lib/mopidy/playlists