Upload files to Firebase Storage using Node.js

Question

I'm trying to understand how to upload files in Firebase Storage, using Node.js. My first try was to use the Firebase library:

"use strict";

var firebase = require('firebase');

var config = {
    apiKey: "AIz...kBY",
    authDomain: "em....firebaseapp.com",
    databaseURL: "https://em....firebaseio.com",
    storageBucket: "em....appspot.com",
    messagingSenderId: "95...6"
};

firebase.initializeApp(config);

// Error: firebase.storage is undefined, so not a function
var storageRef = firebase.storage().ref();

var uploadTask = storageRef.child('images/octofez.png').put(file);

// Register three observers:
// 1. 'state_changed' observer, called any time the state changes
// 2. Error observer, called on failure
// 3. Completion observer, called on successful completion
uploadTask.on('state_changed', function(snapshot){
    ...
}, function(error) {
    console.error("Something nasty happened", error);
}, function() {
  var downloadURL = uploadTask.snapshot.downloadURL;
  console.log("Done. Enjoy.", downloadURL);
});

But it turns out that Firebase cannot upload files from the server side, as it clearly states in the docs:

Firebase Storage is not included in the server side Firebase npm module. Instead, you can use the gcloud Node.js client.

$ npm install --save gcloud

In your code, you can access your Storage bucket using:

var gcloud = require('gcloud')({ ... }); var gcs = gcloud.storage();
var bucket = gcs.bucket('<your-firebase-storage-bucket>');

• Can we use gcloud without having an account on Google Cloud Platform? How?

• If not, how come that uploading files to Firebase Storage from the client side is possible?

• Can't we just create a library that makes the same requests from the server side?

• How is Firebase Storage connected with Google Cloud Platform at all? Why Firebase allows us to upload images only from the client side?

---

My second try was to use the gcloud library, like mentioned in the docs:

var gcloud = require("gcloud");

// The following environment variables are set by app.yaml when running on GAE,
// but will need to be manually set when running locally.
// The storage client is used to communicate with Google Cloud Storage
var storage = gcloud.storage({
  projectId: "em...",
  keyFilename: 'auth.json'
});

storage.createBucket('octocats', function(err, bucket) {

    // Error: 403, accountDisabled
    // The account for the specified project has been disabled.

    // Create a new blob in the bucket and upload the file data.
    var blob = bucket.file("octofez.png");
    var blobStream = blob.createWriteStream();

    blobStream.on('error', function (err) {
        console.error(err);
    });

    blobStream.on('finish', function () {
        var publicUrl = `https://storage.googleapis.com/${bucket.name}/${blob.name}`;
        console.log(publicUrl);
    });

    fs.createReadStream("octofez.png").pipe(blobStream);
});

Answer 1

I have implemented the API to upload the file on the firebase storage:

const fs = require('firebase-admin');
const app = require('express')();
const serviceAccount = require('./serviceAccountKey_DEV.json');

fs.initializeApp({
    credential: fs.credential.cert(serviceAccount),
    storageBucket: `${serviceAccount.project_id}.appspot.com`
});

// Upload the file on firebase storage
app.get("/upload-on-firebase", async (req, res, next) => {
    var bucket = fs.storage().bucket();
    const result = await bucket.upload('data.json');
    console.log('result :', result);
    return res.send(result);
});

Call API to upload:

curl --location --request GET 'http://localhost:3000/upload-on-firebase'

Response:

[
    {
        "_events": {},
        "_eventsCount": 0,
        "metadata": {
            "kind": "storage#object",
            "id": "project_id.appspot.com/data.json/1678222222",
            "selfLink": "https://www.googleapis.com/storage/v1/b/project_id.appspot.com/o/data.json",
            "mediaLink": "https://storage.googleapis.com/download/storage/v1/b/project_id.appspot.com/o/data.json",
            "name": "data.json",
            "bucket": "project_id.appspot.com",
            "generation": "16787922222222",
            "metageneration": "1",
            "contentType": "application/json",
            "storageClass": "STANDARD",
            ....
            ....
            ....
        },
        "baseUrl": "/o",
    }
]

Answer 2

Firebase Admin SDK allows you to directly access your Google Cloud Storage.

For more detail visit Introduction to the Admin Cloud Storage API

var admin = require("firebase-admin");
var serviceAccount = require("path/to/serviceAccountKey.json");

admin.initializeApp({
    credential: admin.credential.cert(serviceAccount),
    storageBucket: "<BUCKET_NAME>.appspot.com"
});

var bucket = admin.storage().bucket();

bucket.upload('Local file to upload, e.g. ./local/path/to/file.txt')

Answer 3

I hope It will useful for you. I uploaded one file from locally and then I added access Token using UUID after that I uploaded into firebase storage.There after I am generating download url. If we hitting that generate url it will automatically downloaded a file.

    const keyFilename="./xxxxx.json"; //replace this with api key file
    const projectId = "xxxx" //replace with your project id
    const bucketName = "xx.xx.appspot.com"; //Add your bucket name
    var mime=require('mime-types');
    const { Storage } = require('@google-cloud/storage');
    const uuidv1 = require('uuid/v1');//this for unique id generation

   const gcs = new Storage({
    projectId: projectId,
    keyFilename: './xxxx.json'
     });
    const bucket = gcs.bucket(bucketName);

    const filePath = "./sample.odp";
    const remotePath = "/test/sample.odp";
    const fileMime = mime.lookup(filePath);

//we need to pass those parameters for this function
    var upload = (filePath, remoteFile, fileMime) => {

      let uuid = uuidv1();

      return bucket.upload(filePath, {
            destination: remoteFile,
            uploadType: "media",
            metadata: {
              contentType: fileMime,
              metadata: {
                firebaseStorageDownloadTokens: uuid
              }
            }
          })
          .then((data) => {

              let file = data[0];

              return Promise.resolve("https://firebasestorage.googleapis.com/v0/b/" + bucket.name + "/o/" + encodeURIComponent(file.name) + "?alt=media&token=" + uuid);
          });
    }
//This function is for generation download url    
 upload(filePath, remotePath, fileMime).then( downloadURL => {
        console.log(downloadURL);

      });

Answer 4

Or you could simply polyfill XmlHttpRequest like so -

const XMLHttpRequest = require("xhr2");
global.XMLHttpRequest = XMLHttpRequest

and import

require('firebase/storage');

That's it. All firebase.storage() methods should now work.

Answer 5

Firebase Storage is now supported by the admin SDK with NodeJS:

https://firebase.google.com/docs/reference/admin/node/admin.storage

// Get the Storage service for the default app
var defaultStorage = firebaseAdmin.storage();
var bucket = defaultStorage.bucket('bucketName');
...

Answer 6

Note that gcloud is deprecated, use google-cloud instead. You can find SERVICE_ACCOUNT_KEY_FILE_PATH at project settings->Service Accounts.

var storage = require('@google-cloud/storage');

var gcs = storage({
    projectId: PROJECT_ID,
    keyFilename: SERVICE_ACCOUNT_KEY_FILE_PATH
  });

// Reference an existing bucket.
var bucket = gcs.bucket(PROJECT_ID + '.appspot.com');

...

Answer 7

When using the firebase library on a server you would typically authorize using a service account as this will give you admin access to the Realtime database for instance. You can use the same Service Account's credentials file to authorize gcloud.

By the way: A Firebase project is essentially also a Google Cloud Platform project, you can access your Firebase project on both https://console.firebase.google.com and https://console.cloud.google.com and https://console.developers.google.com You can see your Project ID on the Firebase Console > Project Settings or in the Cloud Console Dashboard

When using the gcloud SDK make sure that you use the (already existing) same bucket that Firebase Storage is using. You can find the bucket name in the Firebase web config object or in the Firebase Storage tab. Basically your code should start like this:

var gcloud = require('gcloud');

var storage = gcloud.storage({
  projectId: '<projectID>',
  keyFilename: 'service-account-credentials.json'
});

var bucket = storage.bucket('<projectID>.appspot.com');

...