Issue 1 — Discord Audio (PulseAudio)

docker-compose.yml: Added a pulse_socket named volume mounted at /run/pulse in both op25 and edge-node. Also set PULSE_SERVER=unix:/run/pulse/native in edge-node so libpulse (and ffmpeg's pulse input) finds the right socket.

discord_radio.py: Removed _icecast_url and changed _play_stream() to use -f pulse -i default.monitor. This reads directly from the PulseAudio sink monitor — zero buffer delay. The PULSE_SERVER env var is inherited by the ffmpeg subprocess.

Note: default.monitor captures whatever audio is playing on the default sink. If OP25 uses a named virtual sink, you may need to replace default.monitor with <sink_name>.monitor (run pactl list sinks short inside the op25 container to find the name).

Issue 2 — No audio URL / GCS credentials

storage.py: storage.Client() was using ADC but ADC isn't configured in the container. Now uses storage.Client.from_service_account_json(settings.gcp_credentials_path) when GCP_CREDENTIALS_PATH is set — same credential file Firebase already loads.

You also need to mount the key file into the server container in docker-compose.yml:

c2-core:
  volumes:
    - ./gcp-key.json:/app/gcp-key.json:ro
And set GCS_BUCKET=your-bucket-name in .env.

Issue 3 — Token orphaning

mqtt_manager.py: Every checkin now includes "discord_connected": radio_bot.is_connected.

mqtt_handler.py: On checkin, if discord_connected is explicitly False, calls release_token(node_id). Only fires on explicit false (missing field = unknown = no action).

node_sweeper.py: When a node is swept to offline, its token is released too. This covers the case where the node stops checking in entirely (crash/power loss).

drb-edge-node/app/internal/discord_radio.py

@@ -2,7 +2,6 @@ import asyncio
 from typing import Optional
 import discord
 from discord.ext import commands
-from app.config import settings
 from app.internal.logger import logger
 
 BOT_READY_TIMEOUT = 15   # seconds to wait for Discord bot to become ready
@@ -18,9 +17,6 @@ class RadioBot:
         self._watchdog_task: Optional[asyncio.Task] = None
         self._ready_event: Optional[asyncio.Event] = None
         self._current_token: Optional[str] = None
-        self._icecast_url = (
-            f"http://{settings.icecast_host}:{settings.icecast_port}{settings.icecast_mount}"
-        )
 
         # Remembered so we can rejoin after an unexpected disconnect
         self._guild_id: Optional[int] = None
@@ -114,9 +110,11 @@ class RadioBot:
     def _play_stream(self):
         if not self._voice_client:
             return
+        # Read directly from PulseAudio monitor (zero-delay, no Icecast buffer).
+        # PULSE_SERVER is set in the container environment to the shared socket.
         source = discord.FFmpegPCMAudio(
-            self._icecast_url,
-            before_options="-reconnect 1 -reconnect_streamed 1 -reconnect_delay_max 5",
+            "default.monitor",
+            before_options="-f pulse",
         )
         self._voice_client.play(
             discord.PCMVolumeTransformer(source, volume=1.0),

drb-edge-node/app/internal/mqtt_manager.py

@@ -141,11 +141,13 @@ class MQTTManager:
             self._publish(self._t_key_request, {}, qos=1)
 
     async def _publish_checkin(self):
+        from app.internal.discord_radio import radio_bot
         payload = {
             "node_id": settings.node_id,
             "name": settings.node_name,
             "lat": settings.node_lat,
             "lon": settings.node_lon,
+            "discord_connected": radio_bot.is_connected,
             "timestamp": datetime.now(timezone.utc).isoformat(),
         }
         self._publish(self._t_checkin, payload, qos=1)