使用Google Cloud Functions创建Webhook时遇“服务不可用”问题求助

问题现象 #

部署Cloud Functions后，使用Cloud Shell测试接口返回Service Unavailable，测试命令：

curl -m 70 -X POST https://us-central1-webhookattentive.cloudfunctions.net/function-2 \
-H "Authorization: bearer $(gcloud auth print-identity-token)" \
-H "Content-Type: application/json" \
-d '{}'

查看函数日志，发现端口占用错误：

Error: listen EADDRINUSE: address already in use :::8080 at
Server.setupListenHandle [as _listen2] 
(node:net:1740:16) at listenInCluster (node:net:1788:12) at 
Server.listen (node:net:1876:7) at 
main (/layers/google.nodejs.functions-framework/functions-framework/node_modules/@google-cloud/functions-framework/build/src/main.js:45:14)

问题原因 #

代码中手动调用了app.listen(8080)启动Express服务器，但Cloud Functions的运行环境会通过Functions Framework自动监听端口（默认8080），手动启动服务器会和Framework的监听进程端口冲突，导致地址被占用。

修复步骤 #

删除代码中手动启动服务器的部分，移除以下代码段：

// Start the server
app.listen(8080, () => {
  console.log('Server running on port 8080');
});

Cloud Functions会自动加载你导出的Express app实例，无需手动启动服务器。

修复后的完整代码 #

const express = require('express');
const { Storage } = require('@google-cloud/storage');
const app = express();

app.use(express.json());

// Create a new instance of the Storage client
const storage = new Storage();

// Define your Google Cloud Storage bucket name
const bucketName = 'attentivesignup';

app.post('/webhook', async (req, res) => {
  const webhookPayload = req.body;
  
  // Write the webhook payload to a file in Google Cloud Storage
  const filename = `webhook-${Date.now()}.json`;
  const file = storage.bucket(bucketName).file(filename);
  
  await file.save(JSON.stringify(webhookPayload), {
    contentType: 'application/json',
    gzip: true,
  });

  console.log(`Webhook payload saved to: gs://${bucketName}/${filename}`);
  
  // Send a response back to Attentive
  res.status(200).send('Webhook received successfully');
});

exports.webhook = app;

验证方法 #

1. 重新部署Cloud Functions
2. 再次使用之前的curl命令测试接口，此时应返回Webhook received successfully
3. 查看GCS存储桶，确认webhook payload已被保存为JSON文件

内容的提问来源于stack exchange，提问作者npatrick