#!/usr/bin/env python3 """Prometheus exporter for uno-q-audio-synth pipeline. Exposes MIDI, audio, and service health metrics on :9090/metrics. No external dependencies — uses only stdlib. """ import http.server, time, os, re, subprocess, socket, threading PORT = int(os.environ.get("METRICS_PORT", "9090")) SSH_KEY = os.environ.get("SSH_KEY", "/home/david/.ssh/unoq_deploy_key") BOARD = os.environ.get("BOARD_HOST", "127.0.0.1") COLLECT_INTERVAL = 5 # seconds between metric collections # ── Counters ── midi_notes_on = 0 midi_notes_off = 0 midi_errors = 0 # ── Gauges (updated by collector) ── metrics = { "synth_alsa_running": 0, "synth_hw_ptr_bytes_per_sec": 0, "synth_alsa_hw_ptr": 0, "synth_pd_running": 0, "synth_midi_bridge_running": 0, "synth_viz_running": 0, "synth_hphl_switch": 0, "synth_hphr_switch": 0, "synth_hphl_volume": 0, "synth_hphr_volume": 0, "synth_up": 1, } prev_hw_ptr = 0 prev_hw_ptr_time = 0 def read_local_file(path): try: with open(path) as f: return f.read() except (OSError, PermissionError): return "" def get_alsa_status(): """Read ALSA PCM status from /proc.""" global prev_hw_ptr, prev_hw_ptr_time status = read_local_file("/proc/asound/card0/pcm0p/sub0/status") metrics["synth_alsa_running"] = 1 if "RUNNING" in status else 0 m = re.search(r"hw_ptr\s*:\s*(\d+)", status) if m: hw_ptr = int(m.group(1)) now = time.monotonic() metrics["synth_alsa_hw_ptr"] = hw_ptr if prev_hw_ptr_time > 0: dt = now - prev_hw_ptr_time if dt > 0: rate = (hw_ptr - prev_hw_ptr) / dt metrics["synth_hw_ptr_bytes_per_sec"] = max(0, rate) prev_hw_ptr = hw_ptr prev_hw_ptr_time = now def check_service(name): """Check if a systemd service is active (local only).""" try: r = subprocess.run( ["systemctl", "is-active", name], capture_output=True, text=True, timeout=5 ) return 1 if r.stdout.strip() == "active" else 0 except Exception: return 0 def get_mixer_value(name): """Read an ALSA mixer value via amixer.""" try: r = subprocess.run( ["amixer", "-c", "0", "cget", f"name={name}"], capture_output=True, text=True, timeout=5 ) for line in r.stdout.splitlines(): if "values=" in line and line.strip().startswith(":"): val = line.split("values=")[-1].strip() try: return int(val) except ValueError: return 1 if val in ("on", "LOHIFI") else 0 except Exception: return 0 return 0 def collect_metrics(): """Background thread: poll system state periodically.""" while True: try: get_alsa_status() metrics["synth_pd_running"] = check_service("pd-synth-onboard") metrics["synth_midi_bridge_running"] = check_service("midi-bridge") metrics["synth_viz_running"] = check_service("led-matrix-viz") metrics["synth_hphl_switch"] = get_mixer_value("HPHL Switch") metrics["synth_hphr_switch"] = get_mixer_value("HPHR Switch") metrics["synth_hphl_volume"] = get_mixer_value("HPHL Volume") metrics["synth_hphr_volume"] = get_mixer_value("HPHR Volume") except Exception: pass time.sleep(COLLECT_INTERVAL) def format_metrics(): lines = [] lines.append("# HELP synth_midi_notes_on_total Total MIDI note-on messages received") lines.append("# TYPE synth_midi_notes_on_total counter") lines.append(f"synth_midi_notes_on_total {midi_notes_on}") lines.append("# HELP synth_midi_notes_off_total Total MIDI note-off messages received") lines.append("# TYPE synth_midi_notes_off_total counter") lines.append(f"synth_midi_notes_off_total {midi_notes_off}") lines.append("# HELP synth_midi_errors_total Total MIDI parse errors") lines.append("# TYPE synth_midi_errors_total counter") lines.append(f"synth_midi_errors_total {midi_errors}") lines.append("# HELP synth_alsa_running Whether ALSA device is RUNNING") lines.append("# TYPE synth_alsa_running gauge") lines.append(f"synth_alsa_running {metrics['synth_alsa_running']}") lines.append("# HELP synth_hw_ptr_bytes_per_sec Audio throughput in bytes/sec") lines.append("# TYPE synth_hw_ptr_bytes_per_sec gauge") lines.append(f"synth_hw_ptr_bytes_per_sec {metrics['synth_hw_ptr_bytes_per_sec']:.0f}") lines.append("# HELP synth_alsa_hw_ptr Current ALSA hardware pointer") lines.append("# TYPE synth_alsa_hw_ptr gauge") lines.append(f"synth_alsa_hw_ptr {metrics['synth_alsa_hw_ptr']}") lines.append("# HELP synth_pd_running Whether Pd service is active") lines.append("# TYPE synth_pd_running gauge") lines.append(f"synth_pd_running {metrics['synth_pd_running']}") lines.append("# HELP synth_midi_bridge_running Whether midi-bridge service is active") lines.append("# TYPE synth_midi_bridge_running gauge") lines.append(f"synth_midi_bridge_running {metrics['synth_midi_bridge_running']}") lines.append("# HELP synth_viz_running Whether led-matrix-viz service is active") lines.append("# TYPE synth_viz_running gauge") lines.append(f"synth_viz_running {metrics['synth_viz_running']}") lines.append("# HELP synth_hphl_switch Headphone left switch state") lines.append("# TYPE synth_hphl_switch gauge") lines.append(f"synth_hphl_switch {metrics['synth_hphl_switch']}") lines.append("# HELP synth_hphr_switch Headphone right switch state") lines.append("# TYPE synth_hphr_switch gauge") lines.append(f"synth_hphr_switch {metrics['synth_hphr_switch']}") lines.append("# HELP synth_hphl_volume Headphone left volume (0-20)") lines.append("# TYPE synth_hphl_volume gauge") lines.append(f"synth_hphl_volume {metrics['synth_hphl_volume']}") lines.append("# HELP synth_hphr_volume Headphone right volume (0-20)") lines.append("# TYPE synth_hphr_volume gauge") lines.append(f"synth_hphr_volume {metrics['synth_hphr_volume']}") lines.append("# HELP synth_up Exporter is running") lines.append("# TYPE synth_up gauge") lines.append(f"synth_up {metrics['synth_up']}") return "\n".join(lines) + "\n" class MetricsHandler(http.server.BaseHTTPRequestHandler): def do_GET(self): if self.path == "/metrics": body = format_metrics().encode() self.send_response(200) self.send_header("Content-Type", "text/plain; version=0.0.4; charset=utf-8") self.send_header("Content-Length", str(len(body))) self.end_headers() self.wfile.write(body) elif self.path == "/health": body = b'{"status":"ok"}\n' self.send_response(200) self.send_header("Content-Type", "application/json") self.end_headers() self.wfile.write(body) else: self.send_response(404) self.end_headers() def log_message(self, format, *args): pass # silent def main(): # Start background collector t = threading.Thread(target=collect_metrics, daemon=True) t.start() server = http.server.HTTPServer(("0.0.0.0", PORT), MetricsHandler) print(f"[metrics] Listening on :{PORT}/metrics") server.serve_forever() if __name__ == "__main__": main()