Firebase function (written in NodeJS) to delete file from Cloud Storage when an object is removed from Realtime Database

Question

I am new to NodeJS and I am trying to write the next method for Cloud Functions for Firebase.

What I am trying to achieve:

The function should be triggered when the user removes a Photo object from Firebase DB;
The code should remove the file object from Storage corresponding to the Photo obj.

These is my Firebase DB structure:

photos/{userUID}/{photoUID}

{
"dateCreated":      "2017-07-27T16:40:31.000000Z",
"isProfilePhoto":   true,
"isSafe":           true,
"uid":              "{photoUID}",
"userUID":          "{userUID}"
}

And the Firebase Storage format:

photos/{userUID}/{photoUID}.png

And the NodeJS code that I am using:

    const functions = require('firebase-functions')
    const googleCloudStorage = require('@google-cloud/storage')({keyFilename: 'firebase_admin_sdk.json' })
    const admin = require('firebase-admin')
    const vision = require('@google-cloud/vision')();

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

    exports.sanitizePhoto = functions.database.ref('photos/{userUID}/{photoUID}')
        .onDelete(event => {

            let photoUID = event.data.key
            let userUID = event.data.ref.parent.key

            console.log(`userUID: ${userUID}, photoUID: ${photoUID}`);

            if (typeof photoUID === 'undefined' || typeof userUID === 'undefined') {
                console.error('Error while sanitize photo, user uid or photo uid are missing');
                return
            }

            console.log(`Deleting photo: ${photoUID}`)

            googleCloudStorage.bucket(`photos/${userUID}/${photoUID}.png`).delete().then(() => {
                console.log(`Successfully deleted photo with UID: ${photoUID}, userUID : ${userUID}`)
            }).catch(err => {
                console.log(`Failed to remove photo, error: ${err}`)
            });

        });

While I run it I get the next error: "ApiError: Not found"

I think these part of the code is the the one that causes the issue:

googleCloudStorage.bucket(`photos/${userUID}/${photoUID}.png`).delete()

Thanks in advance for support and patience.

@Jay I made the required changes. – Laur Stefan Jul 28 '17 at 08:33 — Laur Stefan, Jul 28 '17 at 08:33

Laur Stefan · Accepted Answer · 2018-11-07T15:54:03.043

Found the issue, here it is the code that works for me:

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

Realtime Database:

exports.sanitizePhoto = functions.database.ref('photos/{userUID}/{photoUID}').onDelete(event => {

        let photoUID = event.data.key
        let userUID = event.data.ref.parent.key

        console.log(`userUID: ${userUID}, photoUID: ${photoUID}`);

        if (typeof photoUID === 'undefined' || typeof userUID === 'undefined') {
            console.error('Error while sanitize photo, user uid or photo uid are missing');
            return
        }

        console.log(`Deleting photo: ${photoUID}`)

        const filePath = `photos/${userUID}/${photoUID}.png`
        const bucket = googleCloudStorage.bucket('myBucket-12345.appspot.com')
        const file = bucket.file(filePath)

        file.delete().then(() => {
            console.log(`Successfully deleted photo with UID: ${photoUID}, userUID : ${userUID}`)
        }).catch(err => {
            console.log(`Failed to remove photo, error: ${err}`)
        });

    });

Also here is the same code but for Firestore (not sure if it works, as I am not a NodeJS developer and didn't actually test it):

exports.sanitizePhoto = functions.firestore.document('users/{userUID}/photos/{photoUID}').onDelete((snap, context) =>{

    const deletedValue = snap.data();

    let photoUID = context.params.photoUID 
    let userUID = context.params.userUID

    console.log(`userUID: ${userUID}, photoUID: ${photoUID}`);

    if (typeof photoUID === 'undefined' || typeof userUID === 'undefined') {
        console.error('Error while sanitize photo, user uid or photo uid are missing');
        return
    }

    console.log(`Deleting photo: ${photoUID}`)

    const filePath = `photos/${userUID}/${photoUID}.png`
    const bucket = googleCloudStorage.bucket('myBucket-12345.appspot.com')
    const file = bucket.file(filePath)

    file.delete().then(() => {
        console.log(`Successfully deleted photo with UID: ${photoUID}, userUID : ${userUID}`)
    }).catch(err => {
        console.error(`Failed to remove photo, error: ${err}`)
    });

});

Also you can notice that my path changed from:

photos/{userUID}/{photoUID}

to:

users/{userUID}/photos/{photoUID}

Thanks, I am getting a reference Error: googleCloudStorage not defined. I am wondering if I forgot to install something with nom for googleCloud Storage. Any thoughts? — Jeff Padgett, Dec 10 '17 at 19:21
fixed, I had installed googleCloudStorage into the project directory, rather than functions directory. — Jeff Padgett, Dec 11 '17 at 19:30
It's worth noting that as per best practices ([here](https://cloud.google.com/storage/docs/best-practices)), it's not recommended to put userID in the file name. — Colin Ricardo, Mar 03 '19 at 08:40
How to check if file exists (nodejs) ? "Error: No such object" when deleting — Emeric, Jul 06 '19 at 16:31

score 0 · Answer 2 · answered Jul 28 '17 at 03:13

try code this

const gcs  = require('@google-cloud/storage')()

    const fileBucketPush = 'Storage bucket.appspot.com'; // The Storage bucket that contains the file.
    const filePathPush = 'folder/'+nameImage; // File path in the bucket.
    vision.detectSafeSearch(gcs.bucket(fileBucketPush).file(filePathPush))
      .then((results) => {
       ..///

      })
      .catch((err) => {
        console.error('ERROR:', err);
      });

Your Enable the Cloud Vision API ?

Firebase function (written in NodeJS) to delete file from Cloud Storage when an object is removed from Realtime Database

2 Answers2

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