Sendspin client as a Docker container with Bluetooth support

[loryanstrant]

TL;DR version:
Together with my buddy Claude, I "built" a Docker container that allows you to utilise the Linux devices you have around the place, connect them to Bluetooth speakers, and present them in Music Assistant as a Sendspin client.
https://github.com/loryanstrant/Sendspin-client

Why did I build this? Well...
Disclaimer: the following explanation is the ultimate in privilege, however the output is beneficial for everyone. 😉

I recently got an infrared sauna which has Bluetooth speakers and I wanted to automate the full experience - which included the playing of a sauna relaxation playlist.
I'd already set up a Squeezelite instance on an ESP32 unit, but it had connection issues (due to WiFi + Bluetooth A2DP).
So, there was already a Surface Pro 4 running Ubuntu with TouchKio nearby, I thought - why not use that?
I tried setting it up as a Squeezelite client but had some challenges, so thought it would be easier to build something specific that used the hardware available (the Bluetooth controller).

It also presents a little web interface for diagnostics/configuration/monitoring.

Anyway, I hope you find it useful!

[Hedda]

@loryanstrant can I suggest that you also check out this other project and more specifically this related request for that project:

• https://github.com/OHF-Voice/linux-voice-assistant

and

• [REQUEST] "Sendspin protocol" (formerly "Resonate") audio player client optimized for music playback OHF-Voice/linux-voice-assistant#6

as well as

• Replace Wyoming satellite with Linux Voice Assistant OHF-Voice/backlog-issues#45

For the back-story also read these:

• Replace Wyoming satellite with Linux Voice Assistant OHF-Voice/backlog-issues#45

and

• Goals for this project OHF-Voice/linux-voice-assistant#96

[loryanstrant]

I've seen these threads previously (before I created my solution), but how are they relevant?

I don't see a Linux Sendspin client with Bluetooth support in there.

[florian-asche]

You made a really nice web interface.

This would be cool not only for sendspin but for all HA containers that run outside of the HA world. If we move the webinterface outside of the sendspin world, i already build a PI Image with Linux-Voice-Assistant and Snapcast-Client.

We could add Sendspin to that and for the webinterface there is a additional container which not only configure sendspin but all instances. We could add a little schema file for each container on what fields can be configured and then set the .env accordingly.

Configure hardware like Soundcard, Volume, maybe Pipewire configuration and Bluetooth connections.

[trudenboy]

Thank you so much for your work. Very useful solution!

For those running Proxmox VE rather than a standalone Docker host, I've added LXC deployment support in a new lxc/ directory.

The main challenge was Bluetooth — LXC containers can't use AF_BLUETOOTH sockets directly due to kernel namespace limitations. The solution is running bluetoothd on the Proxmox host itself and bind-mounting the D-Bus socket into the container at /bt-dbus. PulseAudio's module-bluetooth-discover then talks to the host's daemon transparently, and a small btctl wrapper handles pairing from inside the container.

Setup is a single script run as root on the PVE host:

bash <(curl -fsSL https://raw.githubusercontent.com/loryanstrant/Sendspin-client/main/lxc/proxmox-create.sh)

It handles the Ubuntu 24.04 template download (Python 3.12 is required), container creation, Bluetooth passthrough config, and runs the installer inside the container automatically.

Tested on PVE 8.4.16 with a Sony WH-1000XM4 — Music Assistant discovery and A2DP audio both working.

Couldn't have debugged the AF_BLUETOOTH kernel namespace issue without a certain AI buddy ;) going down the rabbit hole with me — and only occasionally in circles.

PR: loryanstrant/Sendspin-client#6