feat: add structured logging, process watchdog, and systemd hardening

- Add lib/logger.js: timestamped structured logging with 5MB x 5 file rotation
- Add lib/watchdog.js: generic child process supervisor with rate-limited restarts
- Enhance client.js: WS ping/pong liveness detection, uncaughtException/unhandledRejection handlers, systemd sd-notify integration
- Refactor frpc.js: FrpcManager now delegates to Watchdog instead of manual spawn/exit
- Enhance install.sh: environment file, log directory, systemd resource limits, security hardening, WatchdogSec=60
- Replace all console.log/warn/error with structured logger across modules

Made-with: Cursor

lib/watchdog.js

@@ -0,0 +1,121 @@
+'use strict';
+
+const { spawn }  = require('child_process');
+const log        = require('./logger');
+
+const DEFAULT_MAX_RESTARTS  = 10;
+const DEFAULT_WINDOW_MS     = 300_000; // 5 min
+const DEFAULT_RESTART_DELAY = 3_000;
+
+/**
+ * 通用子进程守护：崩溃自动重启、速率限制、健康回调。
+ *
+ * 用法：
+ *   const wd = new Watchdog('frpc', '/path/to/frpc', ['-c', 'frpc.toml'], {
+ *     maxRestarts: 10,
+ *     windowMs:    300_000,
+ *     onStdout: (line) => { ... },
+ *   });
+ *   wd.start();
+ *   wd.stop();
+ */
+class Watchdog {
+  constructor(name, bin, args = [], opts = {}) {
+    this._name          = name;
+    this._bin           = bin;
+    this._args          = args;
+    this._proc          = null;
+    this._stopped       = false;
+    this._restartTimer  = null;
+    this._onStdout      = opts.onStdout  || null;
+    this._onStderr      = opts.onStderr  || null;
+    this._onExit        = opts.onExit    || null;
+    this._spawnOpts     = opts.spawnOpts || {};
+
+    this._maxRestarts   = opts.maxRestarts  ?? DEFAULT_MAX_RESTARTS;
+    this._windowMs      = opts.windowMs     ?? DEFAULT_WINDOW_MS;
+    this._restartDelay  = opts.restartDelay ?? DEFAULT_RESTART_DELAY;
+
+    this._restartTimes  = []; // timestamps of recent restarts
+  }
+
+  get running() {
+    return !!(this._proc && !this._proc.killed);
+  }
+
+  start() {
+    this._stopped = false;
+    this._spawn();
+  }
+
+  stop() {
+    this._stopped = true;
+    if (this._restartTimer) {
+      clearTimeout(this._restartTimer);
+      this._restartTimer = null;
+    }
+    if (this._proc) {
+      this._proc.kill('SIGTERM');
+      // 强杀兜底
+      const p = this._proc;
+      setTimeout(() => { try { p.kill('SIGKILL'); } catch (_) {} }, 5000);
+      this._proc = null;
+    }
+  }
+
+  _spawn() {
+    if (this._stopped) return;
+
+    log.info(this._name, '启动进程...');
+    const proc = spawn(this._bin, this._args, {
+      stdio: ['ignore', 'pipe', 'pipe'],
+      ...this._spawnOpts,
+    });
+    this._proc = proc;
+
+    proc.stdout.on('data', (d) => {
+      const line = d.toString().trim();
+      if (!line) return;
+      if (this._onStdout) this._onStdout(line);
+      else log.info(this._name, line);
+    });
+
+    proc.stderr.on('data', (d) => {
+      const line = d.toString().trim();
+      if (!line) return;
+      if (this._onStderr) this._onStderr(line);
+      else log.warn(this._name, line);
+    });
+
+    proc.on('error', (err) => {
+      log.error(this._name, '进程启动失败:', err.message);
+    });
+
+    proc.on('exit', (code, signal) => {
+      log.warn(this._name, `进程退出 code=${code} signal=${signal}`);
+      this._proc = null;
+      if (this._onExit) this._onExit(code, signal);
+      if (!this._stopped) this._scheduleRestart();
+    });
+  }
+
+  _scheduleRestart() {
+    const now = Date.now();
+    this._restartTimes.push(now);
+
+    // 只保留窗口内的记录
+    this._restartTimes = this._restartTimes.filter(t => now - t < this._windowMs);
+
+    if (this._restartTimes.length > this._maxRestarts) {
+      log.error(this._name,
+        `${this._windowMs / 1000}s 内重启 ${this._restartTimes.length} 次，超过上限 ${this._maxRestarts}，停止守护`);
+      return;
+    }
+
+    const delay = this._restartDelay * Math.min(this._restartTimes.length, 5);
+    log.info(this._name, `${delay / 1000}s 后重启... (窗口内第 ${this._restartTimes.length} 次)`);
+    this._restartTimer = setTimeout(() => this._spawn(), delay);
+  }
+}
+
+module.exports = { Watchdog };