How to access multiple Realtime Database instances in Cloud Functions for Firebase

Question

I\'m using multiple databases in a Firebase project. Cloud functions for the main (default) database work great, however, I cannot make them work for a secondary database. F

Answer 1

So if both the answers doesn't work.

What happened with me is both the method worked without any error but second instance of database was not getting updated.

I updated npm and firebase CLI it worked.

Also @Dough Stevenson you Passing the URL of the database to the API like this **does** work with the Admin SDK

And this is a good blog from Firebase about the same Firebase Blog : Easier scaling with multi-database support!

Answer 2

With cloud functions > 1.1 now, here is the documentation link that saved my life on this issue.

https://firebase.google.com/docs/database/usage/sharding#connect_your_app_to_multiple_database_instances

So, it looks like this at the top of my my cloud function index.js :

const functions = require('firebase-functions');
const admin = require('firebase-admin');
admin.initializeApp();

const dev = admin.initializeApp({
  databaseURL: "https://appdev.firebaseio.com"
}, 'dev');

const v2 = admin.initializeApp({
  databaseURL: "https://appv2.firebaseio.com"
}, 'v2');

and then, in my clond functions functions code I can do :

//will change stuff on default database
admin.database().ref().child(`stuff/${stuffId}`).set(myStuff)

//will change stuff on my dev database
admin.database(dev).ref().child(`stuff/${stuffId}`).set(myStuff)

//will change stuff on my v2 database
admin.database(v2).ref().child(`stuff/${stuffId}`).set(myStuff)

Answer 3

Here's how to access database by URL using Admin SDK:

let app = admin.app();
let ref = app.database('https://secondary_db_url.firebaseio.com').ref();

Here's an example from Admin SDK integration tests: https://github.com/firebase/firebase-admin-node/blob/master/test/integration/database.js#L52

Answer 4

So it looks like you are trying to access multiple databases using the javascript web client API. Passing the URL of the database to the API like this doesn't work with the Admin SDK:

admin.database('https://secondary_db_url.firebaseio.com').ref(`/testNode`)

Instead, you have to initialize a second app, give it a name, and pass that app around to the Admin SDK APIs. Here's a complete sample that writes the same data to two different database instances in the same project:

const functions = require('firebase-functions')
const admin = require('firebase-admin')
admin.initializeApp(functions.config().firebase)

const otherConfig = Object.assign({}, functions.config().firebase)
otherConfig.databaseURL = 'https://your-other-db.firebaseio.com/'
const otherApp = admin.initializeApp(otherConfig, 'otherAppName')

exports.foo = functions.https.onRequest((req, res) => {
    const data = { foo: 'bar' }
    const p1 = admin.database().ref('data').set(data)
    const p2 = admin.database(otherApp).ref('data').set(data)
    Promise.all([p1, p2]).then(() => {
        res.send("OK")
    })
    .catch(error => {
        res.status(500).send(error)
    })
})