To save stream file directly to GoogleCloudStorage via GoogleCloudFunction

[geoseong]

I want to save stream data directly to GoogleCloudStorage via GoogleCloudFunction Node.js.

I tried some ways but works nothing.
Now i'm trying at localhost server first.

so once I tried to test, this error shown :
req.file.cloudStorageError = err;
TypeError: Cannot set property 'cloudStorageError' of undefined

I want to know how this works and get some clue.. plz help me with do this.

client side code

HTML

    <form data-brackets-id='37' action="http://localhost:8989/fileupload" method="post" enctype="multipart/form-data" name="">
        <input data-brackets-id='38' type="file" name="file" id="file" value="">
        <input data-brackets-id='39' type="button" data-inline="true" value="Input" id="filesubmit">
    </form>

Script

    $('form #filesubmit').on('click', (e)=>{
        var uploadfile = $("input[name=file]")[0].files[0];
        var formData = new FormData(); 
        formData.append("myfile", $("input[name=file]")[0].files[0]); 
        
        console.log('uploadfile', uploadfile, uploadfile.type);
       
        var googleCloud = 'https://us-central1-xxxx-xxxxx.cloudfunctions.net/functionNm';
        var localurl = 'http://localhost:8989/fileupload'
        $.ajax({ 
            url: localurl,  // googleCloud
            data: formData, 
            processData: false, 
            contentType: false, 
            type: 'POST', 
            success: function(data){ 
                console.log('response data', data);
            } 
        });

    });

server side code

// start form
var Storage = require('@google-cloud/storage');
var multiparty = require('multiparty');
var fs = require('fs');
var form = new multiparty.Form();

const storage = Storage({
    projectId: [My Project ID]
});
const bucket = storage.bucket('multilang_service');

function getPublicUrl (filename) {
  return `https://storage.googleapis.com/${CLOUD_BUCKET}/${filename}`;
}

// get field name & value
form.on('field',function(name,value){
  console.log('[?] normal field / name = '+name+' , value = '+value);
});

// file upload handling
form.on('part',function(part){
    var filename;
    var size;
    if (part.filename) {
        filename = part.filename;
        size = part.byteCount;
    }else{
        part.resume();
    }   
    
    const gcsname = Date.now() + filename;
    const file = bucket.file(gcsname);
    const stream = file.createWriteStream({
        metadata: {
          contentType: part.headers['content-type']
        }
    });
    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(form);
    
    part.on('data',function(chunk){
        console.log('[2] '+filename+' read '+chunk.length + 'bytes');
    });

    part.on('end',function(){
        console.log('[4] '+filename+' Part read complete');
    });
});

// track progress
form.on('progress',function(byteRead,byteExpected){
    console.log('[3] Reading total  '+byteRead+'/'+byteExpected);
});

// all uploads are completed
form.on('close',function(){
    res.send('done for test');
});

form.parse(req);
// end form

[geoseong]

I think I solved problem using 'multer.js'.

and
Here's my sample.
and how to use multer between client and server.

var multer  = require('multer');
var storage = multer.memoryStorage()
var upload = multer({ storage: storage })

app.post('/fileupload', upload.single('streamfile'), function (req, res, next) {
//app.post('/fileupload', (req, res) => {
    console.log('fileupload req.file', req.file);
    sendUploadToGCS(req, res, next);
});

function sendUploadToGCS(req, res, next) {

  // start form
    var Storage = require('@google-cloud/storage');
  	var multiparty = require('multiparty');
    var fs = require('fs');
  	var form = new multiparty.Form();
    
    const CLOUD_BUCKET = '[my bucket name]';
    var filename = req.file.originalname;
    
    const storage = Storage({
      projectId: '[my gcp project id]'
    });
    const bucket = storage.bucket('[my bucket name]'');
    function getPublicUrl (filename) {
      return `https://storage.googleapis.com/${CLOUD_BUCKET}/${filename}`;
    }
    const gcsname = Date.now() + filename;
    const file = bucket.file(gcsname);
    const stream = file.createWriteStream({
        metadata: {
          contentType: req.file.mimetype
        }
    });

    console.log('gcsname', gcsname);
    console.log('file', file);
    console.log('stream', stream);

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

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

    stream.end(req.file.buffer);
    
};

I hope this will be helpful.
Thanks.