File upload API endpoint handling uploads to Firebase Cloud Storage | #NodeJS #ExpressJS #Multer #Firebase #GCloudStorage #GCP

index.js

require('dotenv').config();
const express = require('express');
const app = express();
const cors = require('cors');
const bodyParser = require('body-parser');
const { Storage } = require('@google-cloud/storage');
const multer = require('multer');
const port = process.env.API_PORT || 8080;

app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));
app.use(cors());

app.get('/', (req, res) => res.send('Welcome to this file upload API :)'));

// Create new storage instance with Firebase project credentials
const storage = new Storage({
  projectId: process.env.GCLOUD_PROJECT_ID,
  keyFilename: process.env.GCLOUD_APPLICATION_CREDENTIALS,
});

// Create a bucket associated to Firebase storage bucket
const bucket = storage.bucket(process.env.GCLOUD_STORAGE_BUCKET_URL);

// Initiating a memory storage engine to store files as Buffer objects
const uploader = multer({
  storage: multer.memoryStorage(),
  limits: {
    fileSize: 5 * 1024 * 1024, // limiting files size to 5 MB
  },
});

// Upload endpoint to send file to Firebase storage bucket
app.post('/api/upload', uploader.single('image'), async (req, res, next) => {
  try {
    if (!req.file) {
      res.status(400).send('Error, could not upload file');
      return;
    }

    // Create new blob in the bucket referencing the file
    const blob = bucket.file(req.file.originalname);

    // Create writable stream and specifying file mimetype
    const blobWriter = blob.createWriteStream({
      metadata: {
        contentType: req.file.mimetype,
      },
    });

    blobWriter.on('error', (err) => next(err));

    blobWriter.on('finish', () => {
      // Assembling public URL for accessing the file via HTTP
      const publicUrl = `https://firebasestorage.googleapis.com/v0/b/${
        bucket.name
      }/o/${encodeURI(blob.name)}?alt=media`;

      // Return the file name and its public URL
      res
        .status(200)
        .send({ fileName: req.file.originalname, fileLocation: publicUrl });
    });

    // When there is no more data to be consumed from the stream
    blobWriter.end(req.file.buffer);
  } catch (error) {
    res.status(400).send(`Error, could not upload file: ${error}`);
    return;
  }
});

app.listen(port, () =>
  console.log(`File uploader API listening on port ${port}`)
);

I did the same thing, but, for some reason, when i try to see my file at google console, it doesn't load...

I figured out what was wrong!

file.createWriteStream({
    gzip: true,
    // if public is true, the file can be found here: `https://storage.googleapis.com/${bucketName}/${fullPath}`;
    public: false, // media token needed, more restricted and secure
    metadata: {
      contentType: axiosResponse.headers['content-type'],
      metadata: {
        firebaseStorageDownloadTokens: accessToken, // define access token
      },
    }
  });

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