bluetooth.md

Bluetooth

Bluetooth will first need to be enabled on the host system.

Requirements

• Bluetooth libraries
• Bluetooth device paired to host
• asound.conf mounted in /etc/asound.conf
• system_bus_socket mounted

Bluetooth Libraries

You will need to install the following dependencies: bluetooth bluez-alsa-utils alsa-utils, or the equivalent in your distro.

Example for debian: apt -y update && apt -y install bluetooth bluez-alsa-utils alsa-utils

Pairing device

Make sure your device has pairing enabled, then use bluetoothctl scan on until you see its MAC. If you do not know its MAC, look for its name or a name that looks like a speaker, or like the manufacturer's name. Note this down.

bluetoothctl trust YOUR_MAC
bluetoothctl pair YOUR_MAC
bluetoothctl connect YOUR_MAC

Replace YOUR_MAC with the speaker's MAC.

Configuration file

To easily test and to actually use your bluetooth speaker inside the container you will need to make an asound configuration file. Here's a handy template:

pcm.!default {
    type plug
    slave {
        pcm {
            type bluealsa
            device YOUR_MAC
            profile "a2dp"
        }
    }
    hint {
        show on
        description "A_DESCRIPTION"
    }
 }

Replace YOUR_MAC and A_DESCRIPTION with the speaker's MAC and with any description you want, or remove the hint if you do not want a description.

To quickly test if it works, start bluealsa with bluealsa -p a2dp-source -p a2dp-sink --a2dp-volume & Then you can move this file to ~/.asoundrc and use aplay normally aplay /path/to/your/file.wav

Auto-starting bluealsa

Bluealsa needs to always run for this to work. The easiest way to assure this is to add the line to /etc/rc.local before exit 0.

Example rc.local

#!/bin/sh -e
#
# rc.local
#
# This script is executed at the end of each multiuser runlevel.
# Make sure that the script will "exit 0" on success or any other
# value on error.
#
# In order to enable or disable this script just change the execution
# bits.
#
# By default this script does nothing.

# Print the IP address
_IP=$(hostname -I) || true
if [ "$_IP" ]; then
  printf "My IP address is %s\n" "$_IP"
fi
bluealsa -p a2dp-source -p a2dp-sink --a2dp-volume &
exit 0

Then mount it inside your container, and use the special bluetooth image:

image: giof71/squeezelite:debian-alsa-bt-squeezelite-current
volumes:
      - /path/to/asound.conf:/etc/asound.conf:ro
      - /run/dbus/system_bus_socket:/run/dbus/system_bus_socket  

Bonus: Auto-connecting the speaker on startup

Replace YOUR_MAC_HERE with the MAC of your bluetooth speakers. There's also commented out examples of how to add more speakers. On a Pi4B+ 3 speakers were successfully connected and playing different streams at once, though your mileage may vary.

#!/bin/bash
## Usage: bash speaker.sh <speaker> <action>
## Possible actions: connect, disconnect, remove  
## e.g: bash speaker.sh default connect
[[ -z $1 ]] && speaker=default || speaker=$1
[[ -z $2 ]] && action=connect || action=$2

case $speaker in
  default)
    MACs='YOUR_MAC_HERE' # 
  ;;
  ## Example to add another speaker 
  #livingroom)
  #  MACs='YOUR_MAC_HERE' # 
  #;;
  ## Example to add multiple speakers at once
  #both)
  #  MACs=('YOUR_MAC_HERE' 'YOUR_OTHER_MAC_HERE') # 
  #;;
esac

# Check bluetooth power
if ! bluetoothctl show | grep -q "Powered: yes"; then
    bluetoothctl power on
fi

# Check agent 
if ! bluetoothctl show | grep -q "Agent: on"; then
    bluetoothctl agent on
fi

for MAC in ${MACs[@]}; do
  case $action in
    connect)
      echo "Connecting to speaker $MAC!"
      if bluetoothctl info "$MAC" | grep -q "Connected: yes"; then
        echo "Speaker $speaker is already connected!"
        continue
      else
        bluetoothctl trust "$MAC"
        bluetoothctl pair "$MAC"
        bluetoothctl connect "$MAC"
      fi
    ;;
    disconnect)
      bluetoothctl disconnect "$MAC"
    ;;
    remove)
      bluetoothctl disconnect "$MAC"
      bluetoothctl untrust "$MAC"
      bluetoothctl remove "$MAC"
    ;;
  esac
done