Let's say I have a Firebase project named "A". Within this project, I have a Cloud Firestore triggered Firebase function that needs to run when a document within Firestore changes. By default, the Firebase Function will listen to changes within Firestore on project A.
However, let's say I have a particular use case where there is a second Firebase project named "B". I need the Firebase Function within Project A to be triggered on Firestore changes that happen to Firestore within project B.
Is this possible? Firebase docs do show initializing multiple projects, which would allow me to connect to multiple databases as such:
const admin = require("firebase-admin");
const serviceAccount = require("path/to/serviceAccountKey.json");
const secondaryAppConfig = {
credential: admin.credential.cert(serviceAccount),
databaseURL: "https://<DATABASE_NAME>.firebaseio.com"
};
// Initialize another app with a different config
const secondary = firebase.initializeApp(secondaryAppConfig, "secondary");
// Retrieve the database.
const secondaryDatabase = secondary.database();
But this doesn't allow me to trigger a Firestore Triggered Firebase Function on my secondary project. Firebase functions call the firebase-functions methods directly, whereas calling a database calls the initialized project.
const functions = require('firebase-functions');
exports.myFunction = functions.firestore
.document('...')
.onWrite((change, context) => { /* ... */ });
Is what I would like to do possible? Or does anyone have a workaround (other than creating this Firebase Function within project B)?
It's not possible. Cloud Functions triggers can only fire in response to changes in the resources of the project where they are deployed. This is true for all types of triggers, including Firestore.
If you want code to run in response to changes in another project, the function will have to be deploy to that project.
Currently it is only possible for writes to Cloud Firestore to trigger Cloud Functions that are part of the same project. It is not possible to trigger Cloud Functions that are defined in another project.
The typical solution is for example to call a HTTP Function in the secondary project, for which you can then configure the complete URL.
I'm not sure it can be done all in one codebase - that's from a lack of experience though. I'd say, given your setup, your calling function can trigger your callee function via HTTP call (documentation)
This might require a paid Firebase plan, but I'm not certain of it (source)
Related
this is my code
admin.initializeApp({...});
var db = admin.database();
let ref = db.ref(...);
await ref.once("value",function () {...},);
firebase.database().goOffline();
firebase.database().goOnline();
ref.on("value",function () {...},);
);
when i use firebase.database().goOnline(); I get an error
Firebase: No Firebase App '[DEFAULT]' has been created - call Firebase App.initializeApp() (app/no-app).
at app
You're mixing two ways of addressing Firebase.
You can access Firebase through:
Its client-side JavaScript SDK, in which case the entry point is usually called firebase.
Its server-side Node.js SDK, in which case the entry point is usually called admin.
Now you initialize admin, but then try to access firebase.database(). And since you did call admin.initializeApp that's where the error comes from.
My guess is that you're looking for admin.database().goOnline() or db.goOnline().
Also note that there is no reason to toggle goOffline()/goOnline() in the way you do now, and you're typically better off letting Firebase manage that on its own.
I am making a react app where I need to fetch some data using an API.
I want to deploy this app with Netlify so I cannot use a backend. So, I wrote a Firebase Cloud Function to handle the fetching. However, Google wouldn't allow third-party API requests on the free plan.
So either I have to learn using AWS or I will write a backend and deploy using another service.
Honestly, I don't want to do either. So, my question is, can I call this node function directly inside my react app if so how and is it advisable, if not are there any other alternatives?
The function is something like this:
const functions = require("firebase-functions");
const League = require("leagueapiwrapper");
require("dotenv").config();
exports.getFavorites = functions.https.onCall(async (data, context) => {
try {
const LeagueAPI = new League(process.env.API_KEY, Region.TR);
...
The only thing that actually requires node is the leagueapiwrapper package. (Obviously I will get rid of firebase related stuff).
I have a Google Cloud Function that syncs presence information from a Firebase realtime database to a Firestore database (as explained here). This is the relevant Cloud Functions code from the linked example:
const functions = require('firebase-functions');
const admin = require('firebase-admin');
admin.initializeApp();
// Since this code will be running in the Cloud Functions enviornment
// we call initialize Firestore without any arguments because it
// detects authentication from the environment.
const firestore = admin.firestore();
// Create a new function which is triggered on changes to /status/{uid}
// Note: This is a Realtime Database trigger, *not* Cloud Firestore.
exports.onUserStatusChanged = functions.database.ref('/status/{uid}').onUpdate(
(change, context) => {
// Get the data written to Realtime Database
const eventStatus = change.after.val();
// Then use other event data to create a reference to the
// corresponding Firestore document.
const userStatusFirestoreRef = firestore.doc(`status/${context.params.uid}`);
// It is likely that the Realtime Database change that triggered
// this event has already been overwritten by a fast change in
// online / offline status, so we'll re-read the current data
// and compare the timestamps.
return change.after.ref.once('value').then((statusSnapshot) => {
const status = statusSnapshot.val();
console.log(status, eventStatus);
// If the current timestamp for this data is newer than
// the data that triggered this event, we exit this function.
if (status.last_changed > eventStatus.last_changed) {
return null;
}
// Otherwise, we convert the last_changed field to a Date
eventStatus.last_changed = new Date(eventStatus.last_changed);
// ... and write it to Firestore.
return userStatusFirestoreRef.set(eventStatus);
});
});
I recently received an email from Google informing me that I will need to update from NodeJS 6 to NodeJS 8 or 10. As this particular function isn't in production yet, I went ahead and made the configuration change in the Google Cloud Console. I now get the error below. I tried switching back to NodeJS 6, recreating the function from scratch, checking Github issues and other online forums. It appears that my Google Cloud Function is no longer being provided with the necessary environment variables to connect with Firebase/Firestore. However, I'm unsure why that would be the case.
Error: Invalid value for config firebase.databaseURL: undefined
at resourceGetter (/srv/node_modules/firebase-functions/lib/providers/database.js:101:19)
at cloudFunctionNewSignature (/srv/node_modules/firebase-functions/lib/cloud-functions.js:102:13)
at /worker/worker.js:825:24
at <anonymous> at process._tickDomainCallback (internal/process/next_tick.js:229:7)
This error also shows up in the Stackdriver logs for the Cloud Function:
Warning, estimating Firebase Config based on GCLOUD_PROJECT. Initializing firebase-admin may fail
You should redeploy using the Firebase CLI. It does some special things in the environment to help the Firebase Admin SDK initialize correctly without any parameters (adding FIREBASE_CONFIG). It sounds like when you changed the runtime in the console, you also lost this special configuration.
For me, I use firestore, and I was getting the same error as you, so I had to create a real-time database without any record then I set the credentials for the admin like so:
const functions = require("firebase-functions");
const admin = require("firebase-admin");
admin.initializeApp({
databaseURL: "your realtime database url"
});
When you are done, run firebase deploy --only functions to deploy your functions.
Here is your Realtime database URL:
I want to listen to two databases in my google cloud functions so I tried this
const app1 = admin.initializeApp({
credential: admin.credential.cert(serviceAccount),
databaseURL: "https://honey.firebaseio.com"
});
const app2 = admin.initializeApp({
credential: admin.credential.cert(serviceAccount),
databaseURL: "https://honey-d8.firebaseio.com/"
}, 'app2');
// Get the default database instance for an app1
var OperationDB = admin.database().ref();
// Get a database instance for app2
var userDB = admin.database(app2).ref();
then I tried to call the second database
exports.onBoardNewUser = functions.userDB.ref('/Users/').onCreate((snapshot, context) => {
})
whenever I attempt to deploy the file it gives this error
Cannot read property 'ref' of undefined
The two databases are in the same project
I have tried different variations but no luck. what am I doing wrong an how can I fix this ?
You can't attach a Cloud Function to some arbitrary database reference. Cloud Functions database triggers are not like listeners that you get with the client SDKs. It receives events from Realtime Database as they are generated.
You have to use the provided API to build a function that references a particular database and path to receive updates.
You can't reference a database outside of the project where you deployed the function.
You can reference multiple shards of a database within the same project. To do that, you have to specify the name of the shard instance using the provided API. If you don't name the instance in the function builder using the instance() method, you will only receive events from the primary/default shard.
If you want to handle events for all of your shards at the same location in each one, you have to export one function for each shard, and they can each delegate to the same helper function to handle the event.
Below is google cloud function , deployed properly and is working fine
path to function - functions/index.js
const functions = require('firebase-functions');
const admin = require("firebase-admin");
admin.initializeApp();
exports.createUser = functions.firestore
.document('users/{userId}')
.onCreate((snap, context) => {
const newValue = snap.data();
console.log(newValue);
});
how can i access this function's event on successful invocation in node.js app
something like
const myFunctions = require("./functions/index");
myFunctions.createUser().then((data) => {
console.log(data)
})
.catch((err) => {
console.log(err);
})
As of now getting below error
Your createUser Cloud Function is triggered by a Firestore onCreate() event type and therefore will be "triggered when a document is written for the first time", as per the documentation.
The doc also adds the following:
In a typical lifecycle, a Cloud Firestore function does the following:
Waits for changes to a particular document. (In this case when the document is written for the first time)
Triggers when an event occurs and performs its tasks
Receives a data object that contains a snapshot of the data stored in the specified document.
Therefore, if you want to trigger this Cloud Function from "the outside world", e.g. from a node.js app, you need to create a new Firestore document at the corresponding location, i.e. under the users collection. To this end you would use the Node.js Server SDK, see https://cloud.google.com/nodejs/docs/reference/firestore/0.14.x/
Note that you could also trigger it from a client application (web, android, iOS) by creating a new user doc with the corresponding client SDK.
Update following your comments:
You cannot directly "port" and run your code written for Cloud Functions to a Node.js app. You will have to re-develop your solution for Node.js.
In your case you should use the Node.js Server SDK (as mentionned in my comment) and you could use the onSnapshot method of a CollectionReference. See https://cloud.google.com/nodejs/docs/reference/firestore/0.14.x/CollectionReference#onSnapshot
I will try to answer your question, but it's a bit unclear. You asked:
How to get Google cloud function execution event
Well, the event has started when the funcion triggers and your code is running, i.e your line const newValue = snap.data()
Maybe you are looking for a way to do certain tasks, when the trigger has run? You simply just do that from inside the function, and return a promise. If you for example had multiple async tasks to run, you could use a Promise.all([]).