Google Cloud Storage (setting up) NodeJS - node.js

Question

So I am looking at the sample code from Google and I can't work out how do I activate the config file?
https://cloud.google.com/appengine/docs/flexible/nodejs/using-cloud-storage
The sample code:
const {format} = require('util');
const express = require('express');
const Multer = require('multer');
const bodyParser = require('body-parser');
// By default, the client will authenticate using the service account file
// specified by the GOOGLE_APPLICATION_CREDENTIALS environment variable and use
// the project specified by the GOOGLE_CLOUD_PROJECT environment variable. See
// https://github.com/GoogleCloudPlatform/google-cloud-node/blob/master/docs/authentication.md
// These environment variables are set automatically on Google App Engine
const {Storage} = require('#google-cloud/storage');
// Instantiate a storage client
const storage = new Storage();
const app = express();
app.set('view engine', 'pug');
app.use(bodyParser.json());
// Multer is required to process file uploads and make them available via
// req.files.
const multer = Multer({
storage: Multer.memoryStorage(),
limits: {
fileSize: 5 * 1024 * 1024, // no larger than 5mb, you can change as needed.
},
});
// A bucket is a container for objects (files).
const bucket = storage.bucket(process.env.GCLOUD_STORAGE_BUCKET);
// Display a form for uploading files.
app.get('/', (req, res) => {
res.render('form.pug');
});
// Process the file upload and upload to Google Cloud Storage.
app.post('/upload', multer.single('file'), (req, res, next) => {
if (!req.file) {
res.status(400).send('No file uploaded.');
return;
}
// Create a new blob in the bucket and upload the file data.
const blob = bucket.file(req.file.originalname);
const blobStream = blob.createWriteStream();
blobStream.on('error', (err) => {
next(err);
});
blobStream.on('finish', () => {
// The public URL can be used to directly access the file via HTTP.
const publicUrl = format(
`https://storage.googleapis.com/${bucket.name}/${blob.name}`
);
res.status(200).send(publicUrl);
});
blobStream.end(req.file.buffer);
});
const PORT = process.env.PORT || 8080;
app.listen(PORT, () => {
console.log(`App listening on port ${PORT}`);
console.log('Press Ctrl+C to quit.');
});
However when you read https://github.com/GoogleCloudPlatform/google-cloud-node/blob/master/docs/authentication.md it says to set up a config file and do the following
{
"projectId": "grape-spaceship-123",
"keyFilename": "./PROJECT-XXXXXX.json"
}
The keyFilename links to the google generated JSON.
But now how do I tell the sample code above to use that?
NOTE: Adding the config file
const config = require('./config')

Answer 1

I created storage and its work for me:
import { Storage } from '#google-cloud/storage';//may be you need to use require()
import * as path from 'path';
const storage = new Storage({
keyFilename: path.join(__dirname, '../********************.json'),
projectId: '***********Id'
})
const fileBucket = storage.bucket('***********-storage');
Good video about this: https://www.youtube.com/watch?v=pGSzMfKBV9Q