Firestore 使用云功能自动备份？

Question

Firebase 文档建议您部署 App Engine 应用来处理自动 Firestore 导出。

https://firebase.google.com/docs/firestore/solutions/schedule-export

app.js

const axios = require('axios');
const dateformat = require('dateformat');
const express = require('express');
const { google } = require('googleapis');

const app = express();

// Trigger a backup
app.get('/cloud-firestore-export', async (req, res) => {
  const auth = await google.auth.getClient({
    scopes: ['https://www.googleapis.com/auth/datastore']
  });

  const accessTokenResponse = await auth.getAccessToken();
  const accessToken = accessTokenResponse.token;

  const headers = {
    'Content-Type': 'application/json',
    Authorization: 'Bearer ' + accessToken
  };

  const outputUriPrefix = req.param('outputUriPrefix');
  if (!(outputUriPrefix && outputUriPrefix.indexOf('gs://') == 0)) {
    res.status(500).send(`Malformed outputUriPrefix: ${outputUriPrefix}`);
  }

  // Construct a backup path folder based on the timestamp
  const timestamp = dateformat(Date.now(), 'yyyy-mm-dd-HH-MM-ss');
  let path = outputUriPrefix;
  if (path.endsWith('/')) {
    path += timestamp;
  } else {
    path += '/' + timestamp;
  }

  const body = {
    outputUriPrefix: path
  };

  // If specified, mark specific collections for backup
  const collectionParam = req.param('collections');
  if (collectionParam) {
    body.collectionIds = collectionParam.split(',');
  }

  const projectId = process.env.GOOGLE_CLOUD_PROJECT;
  const url = `https://firestore.googleapis.com/v1beta1/projects/${projectId}/databases/(default):exportDocuments`;

  try {
    const response = await axios.post(url, body, { headers: headers });
    res
      .status(200)
      .send(response.data)
      .end();
  } catch (e) {
    if (e.response) {
      console.warn(e.response.data);
    }

    res
      .status(500)
      .send('Could not start backup: ' + e)
      .end();
  }
});

// Index page, just to make it easy to see if the app is working.
app.get('/', (req, res) => {
  res
    .status(200)
    .send('[scheduled-backups]: Hello, world!')
    .end();
});

// Start the server
const PORT = process.env.PORT || 6060;
app.listen(PORT, () => {
  console.log(`App listening on port ${PORT}`);
  console.log('Press Ctrl+C to quit.');
});

package.json

{
  "name": "solution-scheduled-backups",
  "version": "1.0.0",
  "description": "Scheduled Cloud Firestore backups via AppEngine cron",
  "main": "app.js",
  "engines": {
    "node": "8.x.x"
  },
  "scripts": {
    "deploy": "gcloud app deploy --quiet app.yaml cron.yaml",
    "start": "node app.js"
  },
  "author": "Google, Inc.",
  "license": "Apache-2.0",
  "dependencies": {
    "axios": "^0.18.0",
    "dateformat": "^3.0.3",
    "express": "^4.16.4",
    "googleapis": "^38.0.0"
  },
  "devDependencies": {
    "prettier": "^1.16.4"
  }
}

cron.yaml

cron:
- description: "Daily Cloud Firestore Export"
  url: /cloud-firestore-export?outputUriPrefix=gs://BUCKET_NAME[/PATH]&collections=test1,test2
  target: cloud-firestore-admin
  schedule: every 24 hours

问题

但我想知道，是否有可能使用 HTTP 云功能 和 Cloud Scheduler 实现相同的功能？

此 App Engine 代码中是否有我无法通过 HTTP 云函数重现或访问的内容？我的意思是，App Engine 项目在这里真的有必要吗？

注意：这不是基于意见的问题，也不是太宽泛。我想知道我是否需要 App Engine 来实现这种行为，以及为什么。

显然，我不需要将其设置为快速服务器。只是一个普通的 HTTP 云函数，调用时会进行导出。

我会在 Cloud Scheduler 中添加类似以下 cron 作业的内容：

Answer 1

如果您使用 Cloud Scheduler 触发执行备份的功能，则根本不需要 App Engine。