DC-067: graceful shutdown coordinator (EventEmitter, 10s drain, idempotent)

dashcaddy-api/server.js

@@ -252,43 +252,52 @@ process.on('uncaughtException', (error) => {
       log.info('server', 'All feature modules initialized');
     });
 
-    // Graceful shutdown
-    const shutdown = (signal) => {
-      log.info('shutdown', `${signal} received, draining connections...`);
-      
-      const resourceMonitor = require('./src/managers/resource-monitor');
-      const backupManager = require('./src/utilities/backup-manager');
-      const healthChecker = require('./src/monitoring/health-checker');
-      const updateManager = require('./src/managers/update-manager');
-      const selfUpdater = require('./src/docker/self-updater');
-      
-      resourceMonitor.stop();
-      backupManager.stop();
-      healthChecker.stop();
-      updateManager.stop();
-      selfUpdater.stop();
-      
-      try {
-        const dockerMaintenance = require('./src/docker/docker-maintenance');
-        dockerMaintenance.stop();
-      } catch { /* optional */ }
-      
-      try {
-        const logDigest = require('./src/security/log-digest');
-        logDigest.stop();
-      } catch { /* optional */ }
+    // Graceful shutdown (DC-067) — drains in-flight HTTP connections, stops
+    // each manager in deterministic order, emits a 'shutdown' event for any
+    // additional listeners, and force-exits after a 10s drain timeout.
+    // Idempotent: a second SIGTERM during shutdown is a no-op.
+    const {
+      createShutdownCoordinator,
+      installSignalHandlers,
+      DEFAULT_DRAIN_TIMEOUT_MS,
+    } = require('./src/utilities/shutdown');
 
-      server.close(() => {
-        log.info('shutdown', 'HTTP server closed');
-        process.exit(0);
+    const optionalManagers = [];
+    try {
+      optionalManagers.push({
+        name: 'docker-maintenance',
+        stop: () => require('./src/docker/docker-maintenance').stop(),
       });
-      
-      // Force exit after 5s if connections don't drain
-      setTimeout(() => process.exit(0), 5000).unref();
-    };
+    } catch { /* optional module */ }
+    try {
+      optionalManagers.push({
+        name: 'log-digest',
+        stop: () => require('./src/security/log-digest').stop(),
+      });
+    } catch { /* optional module */ }
 
-    process.on('SIGTERM', () => shutdown('SIGTERM'));
-    process.on('SIGINT', () => shutdown('SIGINT'));
+    const coordinator = createShutdownCoordinator({
+      server,
+      log,
+      drainTimeoutMs: DEFAULT_DRAIN_TIMEOUT_MS,
+      managers: [
+        { name: 'resource-monitor', stop: () => require('./src/managers/resource-monitor').stop() },
+        { name: 'backup-manager', stop: () => require('./src/utilities/backup-manager').stop() },
+        { name: 'health-checker', stop: () => require('./src/monitoring/health-checker').stop() },
+        { name: 'update-manager', stop: () => require('./src/managers/update-manager').stop() },
+        { name: 'self-updater', stop: () => require('./src/docker/self-updater').stop() },
+        ...optionalManagers,
+      ],
+    });
+
+    // Expose the shutdown signal as an event so additional listeners can
+    // subscribe without touching this file. The coordinator is an
+    // EventEmitter and emits 'shutdown' on SIGTERM/SIGINT.
+    coordinator.on('shutdown', (signal) => {
+      log.info('shutdown', 'shutdown event observed', { signal });
+    });
+
+    installSignalHandlers(coordinator);
 
   } catch (error) {
     console.error('[FATAL] Server startup failed:', error);