Express, Nodejs use Multer for different Services - node.js

Question

I am using express server and multer for upload file on different services (local, azure, cloudinary, amazon s3 etc).
For that i am using different module of multer multer-azure, multer-cloudinary etc.
I need this configuration will be applied to user wise and that information comes from the database.
So i need a extra call to fetch data from database before multer come in action.
I am able to call database query but when i am trying to call multer function, req parameter coming blank. Here is what i am doing.
var multerUtility = require('./upload/multer.utility');
let multer = new multerUtility().getActiveMulterService();
router.post('/', getMetadataConfiguration, multer, (req, res, next) => {
console.log('========== req ==========', req.file); // It is coming blank
console.log('========== req ==========', req.body); // It is coming blank
});
Here is first middleware function, which fetch data from database to verifiy which service will use to upload file.
function getMetadataConfiguration(res, req, next) {
var conn = new jsforce.Connection({
loginUrl : config.org_url,
});
var records = [];
conn.login(username, password, function(err, userInfo) {
if (err) {
return console.error(err);
}
conn.query("query", (err, result) => {
if(err) {
res.status(500).send(err);
}
console.log('=========== result=========', result);
req.serviceConfig = result.records[0];
next();
});
});
}
And here is my MulterUtility Class to handle configuration:
upload/multer.utility.js
class MulterUtility {
constructor() {
}
getActiveMulterService(req, res, next) {
var multerConfiguration;
if(req.serviceConfig.service == 'azure') {
multerConfiguration = multer({
storage: multerAzure({
connectionString: config.azure.connectionString,
account: config.azure.account,
key: config.azure.key,
container: config.azure.container
})
}).single('image');
} else if(req.serviceConfig.service == 'cloudinary') {
multerConfiguration = multer({
storage: cloudinaryStorage({
cloudinary: cloudinary,
folder: config.storageFolder
// allowedFormats: ['jpg', 'png', 'jpeg']
})
}).single('image');
} else if(req.serviceConfig.service === 'amazon') {
multerConfiguration = multer({
storage: multerS3({
s3: s3,
bucket: 'mycontainer',
acl: 'public-read',
contentType: multerS3.AUTO_CONTENT_TYPE,
metadata: function (req, file, cb) {
cb(null, {fieldName: file.fieldname});
},
key: function (req, file, cb) {
cb(null, Date.now().toString() + '-' + file.originalname)
}
})
}).single('image');
} else if(req.serviceConfig.service === 'local') {
multerConfiguration = multer({
storage: multer.memoryStorage()
}).single('image');
}
return multerConfiguration;
}
}
module.exports = MulterUtility;
After executing multer, i am not recieving a req.file or req.body params what multer sets after uploading file.
For now you can consider the 'local' file upload as mentioned in last condition.

Answer 1

The problem is that you call the method getActiveMulterService once before the router. But you need to call it for each post. Try something like this:
var multerUtility = require('./upload/multer.utility');
let multers = new multerUtility();
router.post('/',
getMetadataConfiguration,
(req, res, next) => multers.getActiveMulterService(req, res, next)(req, res, next),
(req, res, next) => {
console.log('========== req ==========', req.file); // It is coming blank
console.log('========== req ==========', req.body); // It is coming blank
});
And in this function you have arguments in the wrong order:
getMetadataConfiguration(res, req, next)
// ==>
getMetadataConfiguration(req, res, next)

Answer 2

Hi this has largely been answered already. The solution is to manual add your file object back onto your req.body object during the process.
Full solution is found here