Generate signed policy URL for upload via PUT request

generateV4SignedPolicy.js

  async function generateV4SignedPolicy() {
    // The ID of your GCS bucket
    const bucketName = 'your-unique-bucket-name';

    // The ID of your GCS file
    const fileName = 'your-file-name';
  
    const bucket = storage.bucket(bucketName);
    const file = bucket.file(fileName);


    // These options will allow temporary uploading of a file
    // through an HTML form.
    const expires = Date.now() + 10 * 60 * 1000; //  10 minutes
    const options = {
      expires,
      fields: {'x-goog-meta-test': 'data'},
    };


    // Get a v4 signed policy for uploading file
    const [response] = await file.generateSignedPostPolicyV4(options);


    // Create an HTML form with the provided policy
    let output = `<form action="${response.url}" method="POST" 
         enctype="multipart/form-data">\n`;
    // Include all fields returned in the HTML form as they're required
    for (const name of Object.keys(response.fields)) {
      const value = response.fields[name];
      output += `  <input name="${name}" value="${value}" type="hidden"/>\n`;
    }
    output += '  <input type="file" name="file"/><br />\n';
    output += '  <input type="submit" value="Upload File"/><br />\n';
    output += '</form>';


    console.log(output);
  }
  
// Full sample here: 
// https://github.com/googleapis/nodejs-storage/blob/main/samples/generateV4SignedPolicy.js