feat: add Cloud Run support with scale-to-zero

Dockerfile

@@ -1,18 +1,27 @@
-FROM node:20-slim
+## ── Build stage ──────────────────────────────
+FROM node:20-slim AS build
 
 WORKDIR /app
 
-# Copy package files
-COPY package*.json ./
+COPY package*.json tsconfig.json ./
+RUN npm ci
+
+COPY src/ ./src/
+RUN npm run build
 
-# Install dependencies
-RUN npm ci --only=production
+## ── Runtime stage ────────────────────────────
+FROM node:20
 
-# Copy built files
-COPY dist/ ./dist/
+WORKDIR /app
+
+COPY package*.json ./
+RUN npm ci --omit=dev
+
+COPY --from=build /app/dist/ ./dist/
 
-# Set environment variables (override at runtime)
 ENV NODE_ENV=production
 
-# Run the bot
+# Cloud Run requires a listening port
+EXPOSE 8080
+
 CMD ["node", "dist/index.js", "start"]

src/index.ts

@@ -25,8 +25,9 @@ import {
   pathToPixels,
 } from "./pathfinding.js";
 import { resolveBotConfig, type BotConfig } from "./bot-config.js";
+import { startHealthServer } from "./server.js";
 
-// Resolve config from CLI args (--bot=clawd or --bot=gremlin)
+// Resolve config from CLI args, BOT_NAME env var, or default to "clawd"
 const config = resolveBotConfig();
 
 /**
@@ -778,6 +779,15 @@ export default defineAgent({
 
 // Run the agent when executed directly
 if (process.argv[1] === fileURLToPath(import.meta.url)) {
+  // Start HTTP health-check server for Cloud Run (no-op locally if PORT unset).
+  startHealthServer();
+
+  // Graceful shutdown on SIGTERM (sent by Cloud Run before stopping a container).
+  process.on("SIGTERM", () => {
+    console.log("[Bot] SIGTERM received, shutting down gracefully...");
+    process.exit(0);
+  });
+
   cli.runApp(
     new WorkerOptions({
       agent: fileURLToPath(import.meta.url),

src/server.ts

@@ -0,0 +1,21 @@
+import { createServer } from "node:http";
+
+/**
+ * Minimal HTTP health-check server for Cloud Run.
+ *
+ * Cloud Run requires a listening port to manage container lifecycle.
+ * This server responds 200 to all requests — used for both health checks
+ * and wake-up pings from the Cloud Function.
+ */
+export function startHealthServer(): void {
+  const port = parseInt(process.env.PORT || "8080", 10);
+
+  const server = createServer((_req, res) => {
+    res.writeHead(200, { "Content-Type": "text/plain" });
+    res.end("ok");
+  });
+
+  server.listen(port, () => {
+    console.log(`[Health] Listening on port ${port}`);
+  });
+}