Hono + Bun graceful shutdown, handling SIGTERM

[amikofalvy]

I'm trying to figure out the best way to safely shutdown a running instance of Hono without dropping requests that are currently processing.

I'm running hono+bun within a container on GCP Cloud Run. When there is a scale in event Google sends the SIGTERM event to the process.

In Node Express I would do something like the following, how would I implement something similar with Hono + Bun?

const express = require('express');

const app = express();
const PORT = process.env.PORT || 3000;

// Basic route
app.get('/', (req, res) => {
    res.send('Server is running!');
});

// Start the server
const server = app.listen(PORT, () => {
    console.log(`Server is listening on port ${PORT}`);
});

// Graceful shutdown handler
function gracefulShutdown(signal) {
    console.log(`Received signal: ${signal}`);
    console.log('Closing server gracefully...');
    
    server.close(() => {
        console.log('HTTP server closed.');
        process.exit(0); // Exit process when server closes
    });

    // Fallback for pending connections
    setTimeout(() => {
        console.error('Forcing shutdown due to pending connections.');
        process.exit(1); // Exit with error if still not closed
    }, 10000); // Adjust timeout as needed
}

// Handle termination signals
['SIGINT', 'SIGTERM'].forEach(signal => {
    process.on(signal, () => gracefulShutdown(signal));
});

[maou-shonen]

const server  = Bun.serve({
  fetch: app.fetch,
})

server.stop()

[seepine]

Hi, i try it and can work on development

import { Hono } from "hono";

const app = new Hono({ strict: false });

const server = Bun.serve({
  port: 3000,
  fetch: app.fetch,
});

process.once("SIGINT", async () => {
  console.log("shutdown event");
  await new Promise<void>((RES) => setTimeout(RES, 3000));
  console.log("shutdown done");
  server.stop();
  process.exit(0);
});

export default server;

But run with docker, it got error

 7 |       if (typeof entryNamespace?.default?.fetch === 'function')  {
 8 |         const server = Bun.serve(entryNamespace.default);
 9 |         console.debug(`Started ${server.development ? 'development ' : ''}server: ${server.protocol}://${server.hostname}:${server.port}`);
10 |       }
11 |    }, reportError);
12 |    const server = Bun.serve(entryNamespace.default);
     ^
EADDRINUSE: Failed to start server. Is port 3000 in use?
 syscall: "listen"

      at bun:main:12:28

Bun v1.1.42 (Linux arm64)

The Dockerfile

FROM oven/bun:alpine as builder
WORKDIR /workspace
COPY package.json ./
RUN bun install
COPY ./ ./
RUN bun run build

FROM alpine
RUN apk --no-cache add libstdc++
WORKDIR /workspace
COPY --from=builder /workspace/dist/app /workspace/app
EXPOSE 3000
ENTRYPOINT ["./app"]

[seepine]

It must be set development

const server = Bun.serve({
  port: 3000,
  development: false,   // add this
  fetch: app.fetch,
});
export default server