feat: add gunicorn production server with start/stop/restart manager

gunicorn.conf.py

@@ -0,0 +1,45 @@
+# gunicorn.conf.py — Gunicorn configuration for TechDJ
+# Used by production.py. Do not run gunicorn directly without this file.
+#
+# Architecture:
+#   - Gunicorn (eventlet worker, 1 worker) serves the DJ panel app on DJ_PORT.
+#   - post_worker_init spawns the listener app on LISTENER_PORT and starts
+#     background greenlets — all within the same worker process so they share
+#     in-process state (SRT state, pre-roll buffer, queue, etc.).
+
+import os
+import json
+
+# ── Load ports from config.json ──────────────────────────────────────────────
+def _load_cfg():
+    try:
+        with open(os.path.join(os.path.dirname(__file__), 'config.json')) as f:
+            return json.load(f)
+    except Exception:
+        return {}
+
+_cfg = _load_cfg()
+
+# ── Gunicorn settings ─────────────────────────────────────────────────────────
+worker_class = 'eventlet'
+workers      = 1          # Must be 1 — eventlet handles concurrency via greenlets
+                          # and both apps share in-process state.
+bind         = f"{_cfg.get('host', '0.0.0.0')}:{_cfg.get('dj_port', 5000)}"
+timeout      = 0          # Disable worker timeout — long-lived SSE/WS connections.
+keepalive    = 5
+
+# Log format
+accesslog    = '-'        # stdout — production.py redirects to techdj.log
+errorlog     = '-'
+loglevel     = 'info'
+
+
+# ── Hooks ─────────────────────────────────────────────────────────────────────
+def post_worker_init(worker):
+    """Called after the eventlet worker is fully initialised.
+
+    Starts the listener server + background greenlets in the same process
+    as the DJ panel so they share all in-process state.
+    """
+    from server import _start_background_tasks
+    _start_background_tasks()

production.py

@@ -0,0 +1,200 @@
+#!/usr/bin/env python3
+"""
+TechDJ production process manager.
+
+Usage:
+    python production.py start    — start TechDJ in the background
+    python production.py stop     — stop TechDJ
+    python production.py restart  — restart TechDJ
+    python production.py status   — show whether TechDJ is running
+    python production.py logs     — tail the live log output
+"""
+import sys
+import os
+import signal
+import subprocess
+import time
+import json
+
+BASE_DIR     = os.path.dirname(os.path.abspath(__file__))
+PID_FILE     = os.path.join(BASE_DIR, 'techdj.pid')
+LOG_FILE     = os.path.join(BASE_DIR, 'techdj.log')
+CONF_FILE    = os.path.join(BASE_DIR, 'gunicorn.conf.py')
+SERVER_MOD   = 'server:dj_app'
+
+# Prefer the venv's gunicorn if it exists.
+_venv_gunicorn = os.path.join(BASE_DIR, '.venv', 'bin', 'gunicorn')
+GUNICORN = _venv_gunicorn if os.path.exists(_venv_gunicorn) else 'gunicorn'
+
+
+# ── Helpers ───────────────────────────────────────────────────────────────────
+
+def _load_config():
+    try:
+        with open(os.path.join(BASE_DIR, 'config.json')) as f:
+            return json.load(f)
+    except Exception:
+        return {}
+
+
+def _read_pid():
+    try:
+        with open(PID_FILE) as f:
+            return int(f.read().strip())
+    except (FileNotFoundError, ValueError):
+        return None
+
+
+def _is_running(pid):
+    if pid is None:
+        return False
+    try:
+        os.kill(pid, 0)
+        return True
+    except (ProcessLookupError, PermissionError):
+        return False
+
+
+def _check_gunicorn():
+    try:
+        subprocess.check_call(
+            [GUNICORN, '--version'],
+            stdout=subprocess.DEVNULL,
+            stderr=subprocess.DEVNULL,
+        )
+    except (FileNotFoundError, subprocess.CalledProcessError):
+        print(f"ERROR: gunicorn not found at '{GUNICORN}'.")
+        print("       Install it with:  pip install gunicorn")
+        sys.exit(1)
+
+
+# ── Commands ──────────────────────────────────────────────────────────────────
+
+def start():
+    pid = _read_pid()
+    if _is_running(pid):
+        print(f"TechDJ is already running (PID {pid})")
+        return
+
+    _check_gunicorn()
+
+    cfg  = _load_config()
+    host = cfg.get('host', '0.0.0.0')
+    port = cfg.get('dj_port', 5000)
+    lport = cfg.get('listener_port', 5001)
+
+    print(f"Starting TechDJ...")
+    print(f"  DJ panel  : http://{host}:{port}")
+    print(f"  Listener  : http://{host}:{lport}")
+    print(f"  Log file  : {LOG_FILE}")
+
+    cmd = [
+        GUNICORN,
+        '--config',      CONF_FILE,
+        '--daemon',
+        '--pid',         PID_FILE,
+        '--access-logfile', LOG_FILE,
+        '--error-logfile',  LOG_FILE,
+        SERVER_MOD,
+    ]
+
+    try:
+        subprocess.check_call(cmd, cwd=BASE_DIR)
+    except subprocess.CalledProcessError as exc:
+        print(f"ERROR: gunicorn exited with code {exc.returncode}. Check {LOG_FILE}")
+        sys.exit(1)
+
+    # Give gunicorn a moment to write the PID file.
+    for _ in range(10):
+        time.sleep(0.5)
+        pid = _read_pid()
+        if _is_running(pid):
+            break
+    else:
+        print(f"ERROR: TechDJ did not start. Check logs:")
+        _tail_log(20)
+        sys.exit(1)
+
+    print(f"TechDJ started (PID {pid})")
+
+
+def stop():
+    pid = _read_pid()
+    if not _is_running(pid):
+        print("TechDJ is not running.")
+        if os.path.exists(PID_FILE):
+            os.remove(PID_FILE)
+        return
+
+    print(f"Stopping TechDJ (PID {pid})...")
+    os.kill(pid, signal.SIGTERM)
+
+    for _ in range(20):
+        time.sleep(0.5)
+        if not _is_running(pid):
+            break
+    else:
+        print("  Graceful shutdown timed out — sending SIGKILL.")
+        try:
+            os.kill(pid, signal.SIGKILL)
+        except ProcessLookupError:
+            pass
+
+    if os.path.exists(PID_FILE):
+        os.remove(PID_FILE)
+
+    print("TechDJ stopped.")
+
+
+def restart():
+    stop()
+    time.sleep(1)
+    start()
+
+
+def status():
+    pid = _read_pid()
+    if _is_running(pid):
+        cfg   = _load_config()
+        host  = cfg.get('host', '0.0.0.0')
+        port  = cfg.get('dj_port', 5000)
+        lport = cfg.get('listener_port', 5001)
+        print(f"TechDJ is running  (PID {pid})")
+        print(f"  DJ panel  : http://{host}:{port}")
+        print(f"  Listener  : http://{host}:{lport}")
+        print(f"  Log file  : {LOG_FILE}")
+    else:
+        print("TechDJ is NOT running.")
+
+
+def _tail_log(lines=50):
+    if not os.path.exists(LOG_FILE):
+        print(f"No log file at {LOG_FILE}")
+        return
+    subprocess.call(['tail', f'-{lines}', LOG_FILE])
+
+
+def logs():
+    if not os.path.exists(LOG_FILE):
+        print(f"No log file at {LOG_FILE}")
+        sys.exit(1)
+    # Replace this process with tail -f so Ctrl+C works cleanly.
+    os.execvp('tail', ['tail', '-f', LOG_FILE])
+
+
+# ── Entry point ───────────────────────────────────────────────────────────────
+
+COMMANDS = {
+    'start':   start,
+    'stop':    stop,
+    'restart': restart,
+    'status':  status,
+    'logs':    logs,
+}
+
+if __name__ == '__main__':
+    cmd = sys.argv[1] if len(sys.argv) > 1 else 'status'
+    if cmd not in COMMANDS:
+        print(f"Usage: python production.py [{'|'.join(COMMANDS)}]")
+        sys.exit(1)
+    COMMANDS[cmd]()

requirements.txt

@@ -2,6 +2,7 @@
 flask
 flask-socketio
 eventlet
+gunicorn
 python-dotenv
 
 # PyQt6 Native App Dependencies

server.py

@@ -1261,6 +1261,33 @@ def _listener_count_sync_loop():
         _broadcast_listener_count()
 
 
+_background_tasks_started = False
+_background_tasks_lock = threading.Lock()
+
+def _start_background_tasks():
+    """Start the listener server and background greenlets.
+
+    Safe to call multiple times — only the first call has any effect.
+    Called from __main__ (direct run) and from gunicorn's post_worker_init
+    hook (production run via gunicorn.conf.py).
+    """
+    global _background_tasks_started
+    with _background_tasks_lock:
+        if _background_tasks_started:
+            return
+        _background_tasks_started = True
+
+    eventlet.spawn(_listener_count_sync_loop)
+    eventlet.spawn(_transcoder_watchdog)
+    eventlet.spawn(
+        listener_socketio.run,
+        listener_app,
+        host=CONFIG_HOST,
+        port=CONFIG_LISTENER_PORT,
+        debug=False,
+    )
+
+
 if __name__ == '__main__':
     print("=" * 50)
     print("TECHDJ PRO - DUAL PORT ARCHITECTURE")
@@ -1275,9 +1302,6 @@ if __name__ == '__main__':
     print(f"DEBUG: {CONFIG_DEBUG}")
     print("=" * 50)
     print(f"READY: Server ready on {CONFIG_HOST}:{CONFIG_DJ_PORT} & {CONFIG_HOST}:{CONFIG_LISTENER_PORT}")
-    
+
-    # Run both servers using eventlet's spawn
+    _start_background_tasks()
-    eventlet.spawn(_listener_count_sync_loop)
+    dj_socketio.run(dj_app, host=CONFIG_HOST, port=CONFIG_DJ_PORT, debug=False)
-    eventlet.spawn(_transcoder_watchdog)
-    eventlet.spawn(dj_socketio.run, dj_app, host=CONFIG_HOST, port=CONFIG_DJ_PORT, debug=False)
-    listener_socketio.run(listener_app, host=CONFIG_HOST, port=CONFIG_LISTENER_PORT, debug=False)