在 firebase 云函数中使用 express `app.get()` 来访问文件

Question

我尝试将 Firebase 托管与 Firebase 函数结合使用，这样只有拥有有效 Firebase 令牌的用户才能访问 .html 内容。

当访问 Firebase 托管时，我能够在我的 iOS 应用程序中发送令牌，并且我的云函数被调用并成功解码令牌（我在 Firebase 函数日志中看到“ID 令牌正确解码”）。

之后应该打开 index.html，它位于我的 /functions 文件夹的子文件夹 (/myhomepage) 内（因此不在“/public”内）。

我的 App-Browser 中总是出现错误：“Cannot GET /”

Firebase-Functions-Log 显示：“函数执行耗时 1654 毫秒，完成状态码：404”

index.js 里面的代码：

const admin = require("firebase-admin");
const functions = require('firebase-functions');
const express = require('express');
const cookieParser = require('cookie-parser')();
const cors = require('cors')({origin: true});
const app = express();

admin.initializeApp();

let db = admin.firestore();

// Express middleware that validates Firebase ID Tokens passed in the Authorization HTTP header.
// The Firebase ID token needs to be passed as a Bearer token in the Authorization HTTP header like this:
// `Authorization: Bearer <Firebase ID Token>`.
// when decoded successfully, the ID Token content will be added as `req.user`.
const validateFirebaseIdToken = async (req, res, next) => {
  functions.logger.log('Check if request is authorized with Firebase ID token');

  if ((!req.headers.authorization || !req.headers.authorization.startsWith('Bearer ')) &&
      !(req.cookies && req.cookies.__session)) {
    functions.logger.error(
      'No Firebase ID token was passed as a Bearer token in the Authorization header.',
      'Make sure you authorize your request by providing the following HTTP header:',
      'Authorization: Bearer <Firebase ID Token>',
      'or by passing a "__session" cookie.'
    );
    res.status(403).send('Unauthorized');
    return;
  }

  let idToken;
  if (req.headers.authorization && req.headers.authorization.startsWith('Bearer ')) {
    functions.logger.log('Found "Authorization" header');
    // Read the ID Token from the Authorization header.
    idToken = req.headers.authorization.split('Bearer ')[1];
  } else if(req.cookies) {
    functions.logger.log('Found "__session" cookie');
    // Read the ID Token from cookie.
    idToken = req.cookies.__session;
  } else {
    // No cookie
    res.status(403).send('Unauthorized');
    return;
  }

  try {
    const decodedIdToken = await admin.auth().verifyIdToken(idToken);
    functions.logger.log('ID Token correctly decoded', decodedIdToken);
    req.user = decodedIdToken;
    next();
    return;
  } catch (error) {
    functions.logger.error('Error while verifying Firebase ID token:', error);
    res.status(403).send('Unauthorized');
    return;
  }
};

app.use(cors);
app.use(cookieParser);
app.use(validateFirebaseIdToken);
app.get('/myhomepage', (req, res) => { // <-- The problem seems to be here
    functions.logger.log('Calling get.'); // This line does not get called in my log.
    res.status(200).sendFile('/index.html');
});

exports.myfunction = functions.https.onRequest(app);

令牌成功解码后，如何访问“/functions/myhomepage”内的内容？

Answer 1

通常您只能以send()、redirect() 或end() 结束HTTP 函数，请参阅doc。

我从未尝试过，但我认为使用sendFile() 不会奏效。如果您想将用户重定向到通过 Firebase 托管提供的静态页面，您应该使用 redirect()。另一种可能性是将 HTML 字符串传递给 send() 方法，请参阅 here。