Firebase Cloud Function connection error when bucket.upload() - firebase

Question

When I try to upload the generated PDF file to storage bucket, the firebase logs gives me that response after log "Init upload of file...":
Function execution took 3721 ms, finished with status: 'connection
error'
Maybe the problem can be the order of Promises. But I'm beginner with Cloud Functions and Node.js to reorder that.
const functions = require('firebase-functions');
const admin = require('firebase-admin');
const pdf = require('html-pdf');
const gcs = require('#google-cloud/storage')({keyFilename: './service_account.json'});
const handlebars = require('handlebars');
const path = require('path');
const os = require('os');
const fs = require('fs');
const bucket = gcs.bucket(bucketURL);
admin.initializeApp(functions.config().firebase);
var html = null;
exports.generatePdf = functions.https.onRequest((request, response) => {
// data to apply to template file
const user = {
"date": new Date().toISOString(),
"title": "Voucher",
"body": "Voucher body"
};
const options = {
"format": 'A4',
"orientation": "portrait"
};
const localPDFFile = path.join(os.tmpdir(), 'localPDFFile.pdf');
try {
const source = fs.readFileSync(__dirname + '/voucher.html', 'utf8');
html = handlebars.compile(source)(user);
} catch (error) {
console.error(error);
}
const phantomJsCloud = require("phantomjscloud");
const browser = new phantomJsCloud.BrowserApi(phantomApiKey);
var pageRequest = { content: html, renderType: "pdf" };
// // Send our HTML to PhantomJS to convert to PDF
return browser.requestSingle(pageRequest)
.then(function (userResponse) {
if (userResponse.statusCode !== 200) {
console.log("invalid status code" + userResponse.statusCode);
} else {
console.log('Successfully generated PDF');
// Save the PDF locally
fs.writeFile(localPDFFile, userResponse.content.data, {
encoding: userResponse.content.encoding,
}, function (err) {
console.log('Init upload of file...' + localPDFFile);
// Upload the file to our cloud bucket
return bucket.upload(localPDFFile, {
destination: '/pdfs/voucher.pdf',
metadata: {
contentType: 'application/pdf'
}
}).then(() => {
console.log('bucket upload complete: ' + localPDFFile);
response.status(200).send({
message: 'PDF Gerado com sucesso!',
address: localPDFFile
});
return true;
}).catch(error => {
response.status(400).send({
message: 'Error on bucket upload!',
error: error
});
return false;
});
});
return true;
}
return true;
});
})