Code sample to upload files in Google Cloud Storage bucket for Node.js

gcp-storage.js

// Install GCP Client library
//    npm install --save @google-cloud/storage
// To run the client library, you must first set up authentication by creating a service account
// and setting an environment variable. Ask your DevOps person to provide you with service account key
// For example:
//    export GOOGLE_APPLICATION_CREDENTIALS="/home/user/Downloads/[FILE_NAME].json"

// Imports the Google Cloud client library
const { Storage } = require('@google-cloud/storage');

// Creates a GCP Storage client
const storage = new Storage({
    projectId: "some-random-id-1337",
});

// Declare the bucket you wanna upload the files
const bucketName = "exact-bucket-name";
// 
// Downloading non-public file
// 
const srcFilename = "download.zip";
const destFilename = "./download.zip";

// Downloads the file from bucket
await storage
  .bucket(bucketName)
  .file(srcFilename)
  .download({
      destination: destFilename
  });

console.log(`GS://${bucketName}/${srcFilename} downloaded to ${destFilename}.`);

// 
// Uploading a local file to the bucket
// 
await storage.bucket(bucketName).upload("./filename.jpg", {
  destination: "/destination/at/bucket",
  // Support for HTTP requests made with `Accept-Encoding: gzip`
  gzip: true,
  metadata: {
      // Enable long-lived HTTP caching headers
      // Use only if the contents of the file will never change
      // (If the contents will change, use cacheControl: 'no-cache')
      cacheControl: 'public, max-age=31536000',
  },
});

// Upload FileStream
const file = bucket.file(gcsname);

const stream = file.createWriteStream({
    metadata: {
        contentType: req.file.mimetype
    },
    resumable: false
});

stream.on('error', (err) => {
    req.file.cloudStorageError = err;
    next(err);
});

stream.on('finish', () => {
    req.file.cloudStorageObject = gcsname;
    file.makePublic().then(() => {
        req.file.cloudStoragePublicUrl = getPublicUrl(gcsname);
        next();
    });
});

stream.end(req.file.buffer);

console.log(`GS://${fileName} uploaded to ${bucketName}.`);

// This will upload the file but it won't be publicly available
// To make a file public
await storage
  .bucket(bucketName)
  .file(filename)
  .makePublic();

console.log(`gs://${bucketName}/${filename} is now public.`);