File Change

op25-container/system.pa	New PulseAudio config: auth-anonymous=1 so the edge-node can connect without group membership
op25-container/Dockerfile	Copies system.pa into /etc/pulse/system.pa
drb-edge-node/Dockerfile	Added libpulse0 — ffmpeg needs this runtime library to use -f pulse
drb-edge-node/app/internal/call_recorder.py	Switched recording from Icecast (burst-buffer overlap) to PulseAudio monitor (zero-delay, exact call boundaries)

drb-edge-node/Dockerfile

@@ -4,6 +4,7 @@ RUN apt-get update && apt-get install -y \
     ffmpeg \
     libopus0 \
     libopus-dev \
+    libpulse0 \
     && rm -rf /var/lib/apt/lists/*
 
 WORKDIR /app

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

@@ -15,9 +15,6 @@ class CallRecorder:
         self._process: Optional[asyncio.subprocess.Process] = None
         self._current_call_id: Optional[str] = None
         self._current_file: Optional[Path] = None
-        self._icecast_url = (
-            f"http://{settings.icecast_host}:{settings.icecast_port}{settings.icecast_mount}"
-        )
         self._recordings_dir = Path(settings.recordings_path)
 
     async def start_recording(self, call_id: str) -> bool:
@@ -30,10 +27,15 @@ class CallRecorder:
         self._current_file = self._recordings_dir / f"{ts}_{call_id}.mp3"
         self._current_call_id = call_id
 
+        # Read directly from the PulseAudio monitor source (zero-delay, no Icecast burst buffer).
+        # PULSE_SERVER env var is set in the container environment.
         cmd = [
             "ffmpeg", "-y",
-            "-i", self._icecast_url,
+            "-f", "pulse",
-            "-acodec", "copy",
+            "-i", "default.monitor",
+            "-acodec", "libmp3lame",
+            "-ar", "22050",
+            "-b:a", "32k",
             "-t", str(MAX_RECORDING_SECONDS),
             str(self._current_file),
         ]

op25-container/Dockerfile

@@ -9,6 +9,9 @@ RUN apt-get update && \
     apt-get upgrade -y && \
     apt-get install git pulseaudio pulseaudio-utils liquidsoap -y
 
+# Install custom PulseAudio system config (enables anonymous access for edge-node)
+COPY system.pa /etc/pulse/system.pa
+
 # Clone the boatbod op25 repository
 RUN git clone -b gr310 https://github.com/boatbod/op25 /op25
 

op25-container/system.pa

@@ -0,0 +1,16 @@
+# PulseAudio system daemon configuration for DRB containers.
+# Allows anonymous connections so the edge-node container can read the audio monitor.
+
+.nofail
+
+# Native protocol with anonymous auth — required for inter-container access
+load-module module-native-protocol-unix socket=/run/pulse/native auth-anonymous=1
+
+# Always provide a default sink even without audio hardware
+load-module module-always-sink
+
+# Restore device/stream settings across restarts
+load-module module-device-restore
+load-module module-stream-restore
+
+.fail