在同一NodeJS应用程序中使用firebase.database（）和admin.database（）

Question

Most of my application is using firebase.database() and I have only used admin where elevated permissions were required. I just updated to Firebase 4.12.1, once I did that, I started receiving the following error when I used admin.database():

[2018-04-16T13:45:01.042Z] @firebase/database: FIREBASE FATAL ERROR: Database initialized multiple times. Please make sure the format of the database URL matches with each database() call.

I found that if I remove calls for firebase.database() that happen prior to admin.database() I no longer get the issue, but that connection if I go to a subsequent page that does user firebase.database(), I receive the error because the connection already exists.

Is this a bug, am I doing something incorrectly, or can we not use firebase.database() and admin.database() both in the same node application after Firebase 4.10.0(last working version I have)?

app.js(truncated)

var config = {
  apiKey: "XXXX",
  authDomain: "XXXX",
  databaseURL: "https://XXXX.firebaseio.com",
  projectId: "XXXX",
  storageBucket: "XXXX",
  messagingSenderId: "XXXX"
};
firebase.initializeApp(config);

serviceAccount = require(path.join(__dirname, 'XXXXX.json'));
var database = firebase.database();

users.js

var express = require('express');
var router = express.Router();
var firebase = require("firebase");

var admin = require("firebase-admin");
admin.initializeApp({
  credential: admin.credential.cert(serviceAccount),
  databaseURL: "https://XXXX.firebaseio.com"
});
/* GET users listing. */
router.get('/', function(req, res, next) {
  var databaseRef = admin.database().ref('navigator/users');
  var query = databaseRef.once('value').then(function(snapshot) {
    var totalUsers = 0;
    snapshot.forEach(function(element) {
      if(element.child('locations').hasChild('branson')){
        console.log(element.key);
        console.log('');
        totalUsers += 1;
      }
    });
    res.send('totalUsers' + totalUsers);
  });
});

module.exports = router;

Answer 1

You should not use the Admin SDK and the regular Firebase JavaScript SDK in a single page. In fact, the Admin SDK is meant for use in Node.js projects, not in web pages.

While it is possible to use the Admin SDK in a web page in some cases, I'd seriously consider against it. Unless you know exactly what is being accessed where, you run a risk of someone getting hold of your administrative credentials and gaining full access to your project. At the very least you'll want to host the pages that use the Admin SDK in a place that cannot be accessed by a regular user.

If you continue using the Admin SDK in a web page, you should then use a page reload when transitioning from a page that uses the client SDK to a page that uses the Admin SDK. That way each page will have only one or the other loaded, and the conflict won't arise.