Get Download URL from file uploaded with Cloud Functions for Firebase

As of firebase 6.0.0 I was able to access the storage directly with the admin like this:

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

So I didn't need to add a service account. Then setting the UUID as referenced above worked for getting the firebase url.

If you're working on a Firebase project, you can create signed URLs in a Cloud Function without including other libraries or downloading a credentials file. You just need to enable the IAM API and add a role to your existing service account (see below).

Initialize the admin library and get a file reference as your normally would:

import * as functions from 'firebase-functions'
import * as admin from 'firebase-admin'

admin.initializeApp(functions.config().firebase)

const myFile = admin.storage().bucket().file('path/to/my/file')

You then generate a signed URL with

myFile.getSignedUrl({action: 'read', expires: someDateObj}).then(urls => {
const signedUrl = urls[0]
})

**Make sure your Firebase service account has sufficient permissions to run this**

1. Go to the Google API console and enable the IAM API (

[To see links please register here]

)
2. Still in the API console, go to the main menu, "IAM & admin" -> "IAM"
3. Click edit for the "App Engine default service account" role
4. Click "Add another role", and add the one called "Service Account Token Creator"
5. Save and wait a minute for the changes to propagate

With a vanilla Firebase config, the first time you run the above code you'll get an error *Identity and Access Management (IAM) API has not been used in project XXXXXX before or it is disabled.*. If you follow the link in the error message and enable the IAM API, you'll get another error: *Permission iam.serviceAccounts.signBlob is required to perform this operation on service account my-service-account*. Adding the Token Creator role fixes this second permission issue.

If you use the predefined access control lists value of 'publicRead', you can upload the file and access it with a very simple url structure:

// Upload to GCS
const opts: UploadOptions = {
gzip: true,
destination: dest, // 'someFolder/image.jpg'
predefinedAcl: 'publicRead',
public: true
};
return bucket.upload(imagePath, opts);

You can then construct the url like so:

const storageRoot = 'https://storage.googleapis.com/';
const bucketName = 'myapp.appspot.com/'; // CHANGE TO YOUR BUCKET NAME
const downloadUrl = storageRoot + bucketName + encodeURIComponent(dest);

This is the best I came up. It is redundant, but the only reasonable solution that worked for me.

await bucket.upload(localFilePath, {destination: uploadPath, public: true});
const f = await bucket.file(uploadPath)
const meta = await f.getMetadata()
console.log(meta[0].mediaLink)

You'll need to generate a signed URL using [getSignedURL][1] via the [@google-cloud/storage][2] NPM module.

Example:

const gcs = require('@google-cloud/storage')({keyFilename: 'service-account.json'});
// ...
const bucket = gcs.bucket(bucket);
const file = bucket.file(fileName);
return file.getSignedUrl({
action: 'read',
expires: '03-09-2491'
}).then(signedUrls => {
// signedUrls[0] contains the file's public URL
});

You'll need to initialize `@google-cloud/storage` with [your service account credentials][3] as the application default credentials will not be sufficient.

**UPDATE**: The Cloud Storage SDK can now be accessed via the Firebase Admin SDK, which [acts as a wrapper][4] around @google-cloud/storage. The only way it will is if you either:

1. Init the SDK with a special service account, typically through a second, non-default instance.
2. Or, without a service account, by giving the default App Engine service account the "signBlob" permission.


[1]:

[To see links please register here]

[2]:

[To see links please register here]

[3]:

[To see links please register here]

[4]:

[To see links please register here]

If you are getting error:

> Google Cloud Functions: require(…) is not a function

try this:


const {Storage} = require('@google-cloud/storage');
const storage = new Storage({keyFilename: 'service-account-key.json'});
const bucket = storage.bucket(object.bucket);
const file = bucket.file(filePath);
.....

Without `signedURL()` using `makePublic()`

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

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

// --- [Above] for admin related operations, [Below] for making a public url from a GCS uploaded object

const { Storage } = require('@google-cloud/storage');
const storage = new Storage();

exports.testDlUrl = functions.storage.object().onFinalize(async (objMetadata) => {
console.log('bucket, file', objMetadata.bucket + ' ' + objMetadata.name.split('/').pop()); // assuming file is in folder
return storage.bucket(objMetadata.bucket).file(objMetadata.name).makePublic().then(function (data) {
return admin.firestore().collection('publicUrl').doc().set({ publicUrl: 'https://storage.googleapis.com/' + objMetadata.bucket + '/' + objMetadata.name }).then(writeResult => {
return console.log('publicUrl', writeResult);
});
});
});

I already post my ans... in below URL Where you can get full code with solution

[To see links please register here]

const uuidv4 = require('uuid/v4');
const uuid = uuidv4();

const os = require('os')
const path = require('path')
const cors = require('cors')({ origin: true })
const Busboy = require('busboy')
const fs = require('fs')
var admin = require("firebase-admin");


var serviceAccount = {
"type": "service_account",
"project_id": "xxxxxx",
"private_key_id": "xxxxxx",
"private_key": "-----BEGIN PRIVATE KEY-----\jr5x+4AvctKLonBafg\nElTg3Cj7pAEbUfIO9I44zZ8=\n-----END PRIVATE KEY-----\n",
"client_email": "[email protected]",
"client_id": "xxxxxxxx",
"auth_uri": "https://accounts.google.com/o/oauth2/auth",
"token_uri": "https://oauth2.googleapis.com/token",
"auth_provider_x509_cert_url": "https://www.googleapis.com/oauth2/v1/certs",
"client_x509_cert_url": "https://www.googleapis.com/robot/v1/metadata/x509/firebase-adminsdk-5rmdm%40xxxxx.iam.gserviceaccount.com"
}

admin.initializeApp({
credential: admin.credential.cert(serviceAccount),
storageBucket: "xxxxx-xxxx" // use your storage bucket name
});


const app = express();
app.use(bodyParser.urlencoded({ extended: false }));
app.use(bodyParser.json());
app.post('/uploadFile', (req, response) => {
response.set('Access-Control-Allow-Origin', '*');
const busboy = new Busboy({ headers: req.headers })
let uploadData = null
busboy.on('file', (fieldname, file, filename, encoding, mimetype) => {
const filepath = path.join(os.tmpdir(), filename)
uploadData = { file: filepath, type: mimetype }
console.log("-------------->>",filepath)
file.pipe(fs.createWriteStream(filepath))
})

busboy.on('finish', () => {
const bucket = admin.storage().bucket();
bucket.upload(uploadData.file, {
uploadType: 'media',
metadata: {
metadata: { firebaseStorageDownloadTokens: uuid,
contentType: uploadData.type,
},
},
})

.catch(err => {
res.status(500).json({
error: err,
})
})
})
busboy.end(req.rawBody)
});




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

answer by

[To see links please register here]

works best

const uploadOptions: UploadOptions = {
public: true
};

const bucket = admin.storage().bucket();
[ffile] = await bucket.upload(oPath, uploadOptions);
ffile.metadata.mediaLink // this is what you need

For those trying to use the token parameter to share the file and would like to use gsutil command, here is how I did it:

First you need to authenticate by running: `gcloud auth`

Then run:

`gsutil setmeta -h "x-goog-meta-firebaseStorageDownloadTokens:$FILE_TOKEN"` `gs://$FIREBASE_REPO/$FILE_NAME`

Then you can download the file with the following link:

[To see links please register here]

$FIREBASE_REPO/o/$FILE_NAME?alt=media&token=$FILE_TOKEN