implemented a lot of features

app/services/Shutdown.ts

@@ -0,0 +1,45 @@
+import { setTimeout as sleep } from 'node:timers/promises'
+
+/** After a signal, give cleanup this long before exiting anyway. */
+const FORCE_EXIT_MS = 25_000
+
+/**
+ * Graceful shutdown for the long-running commands. SIGTERM (docker stop) and
+ * SIGINT wake up `wait()` and `sleep()`, so workers can finish their active
+ * jobs and close their connections before the process exits.
+ */
+class Shutdown {
+  private readonly controller = new AbortController()
+
+  constructor() {
+    for (const signal of ['SIGTERM', 'SIGINT'] as const) {
+      process.once(signal, () => {
+        this.controller.abort()
+        setTimeout(() => process.exit(0), FORCE_EXIT_MS).unref()
+      })
+    }
+  }
+
+  get requested(): boolean {
+    return this.controller.signal.aborted
+  }
+
+  /** Resolves when a shutdown signal arrives. */
+  wait(): Promise<void> {
+    if (this.requested) return Promise.resolve()
+    return new Promise((resolve) =>
+      this.controller.signal.addEventListener('abort', () => resolve(), { once: true })
+    )
+  }
+
+  /** Sleeps, but returns early on shutdown. */
+  async sleep(ms: number): Promise<void> {
+    try {
+      await sleep(ms, undefined, { signal: this.controller.signal })
+    } catch {
+      // aborted by a shutdown signal
+    }
+  }
+}
+
+export default new Shutdown()