Express Router - uploading to S3 and MongoDb - node.js

Question

I'm trying to do the following in Node.js using express router, Multer-S3, Multer, AWS and Mongodb.
I want to:
1: Check if filetype is image, price is number etc (some kind of quality check)
2: If above true, upload image to S3 to get Image url
3: If Image Url was generated, upload to Mongodb, including the generated image url..
Trying with below code but can only get one of these to work at same time..
const express = require("express");
const router = express.Router();
const shopController = require("../controllers/shop");
router.post(
"/shop/create/:shopId",
shopController.creatingShop,
shopController.createShopItem
);
const ShopItem = require("../models/shopitem"); //Mongoose Schema
const multer = require("multer");
const fileview = multer().single("file1"); //Trying to use this to view file before uploading to S3
const uploader = require("../services/file-upload");
const singleUpload = uploader.single("file1"); //Using this to upload to S3
exports.createShopItem = (req, res, next) => {
fileview(req, res, function (err) {
const file = req.file;
const title = req.body.title;
const price = req.body.price;
const description = req.body.description;
const location = req.body.location;
const user = "OrreSnorre";
if (
file.mimetype != "image/jpeg" &&
file.mimetype != "image/jpg" &&
file.mimetype != "image/png"
) {
return next(new Error("invalid file type"));
}
if (file.size > 2500000) {
return next(new Error("Your image is to big. Maximum 2.5mb"));
}
next();
console.log(
"Here I want to add upload text to mongoDb... including URL from S3 after it is generated"
);
});
exports.creatingShop = (req, res, next) => {
singleUpload(req, res, function (err) {
console.log(req.file);
// res.json({ "image-url": req.file.location });
});
next();
};
Anyone got ideas? Or examples that work?
Best regards,
Oscar

Answer 1

There are 2 ways to do this, either you can use only multer or multer-s3.
For simplicity, I will show you the way using only multer.
Flow of processing as follow:
Multer process and save to local
You read from local, and upload to s3 using s3 SDK (You should explore how to remove the file after upload as well, but I wont clutter you with this logic here)
If upload is successful, you retrieve the URL and pass it to your MongoDB.
// Make "temp" directory as multer.diskStorage wont create folder
fs.mkdir('./temp', { recursive: true }, (err) => {
if (err) throw err;
});
const PORT = parseInt(process.argv[2]) || parseInt(process.env.PORT) || 3000;
// Multer
const storage = multer.diskStorage({
destination: function (req, file, cb) {
cb(null, './temp');
},
filename: function (req, file, cb) {
let extArray = file.mimetype.split('/');
let extension = extArray[extArray.length - 1];
cb(null, new Date().getTime() + '.' + extension);
},
});
const upload = multer({ storage: storage });
const endpoint = new AWS.Endpoint(AWS_S3_HOSTNAME);
const s3 = new AWS.S3({
endpoint,
accessKeyId: AWS_S3_ACCESSKEY_ID,
secretAccessKey: AWS_S3_SECRET_ACCESSKEY,
});
// Get the uploaded file in local here
const readFile = (path) =>
new Promise((resolve, reject) =>
fs.readFile(path, (err, buff) => {
if (null != err) reject(err);
else resolve(buff);
})
// Upload to AWS S3 here
const putObject = (file, buff, s3) =>
new Promise((resolve, reject) => {
const params = {
Bucket: AWS_S3_BUCKET_NAME,
Key: file.filename,
Body: buff,
ACL: 'public-read',
ContentType: file.mimetype,
ContentLength: file.size,
};
s3.putObject(params, (err, result) => {
if (null != err) reject(err);
else resolve(file.filename);
});
});
);
const mongoClient = new MongoClient(MONGO_URL, {
useNewUrlParser: true,
useUnifiedTopology: true,
});
app.post('/api/post', upload.single('imageFile'), async (req, res) => {
readFile(req.file.path)
.then((buff) =>
// Insert Image to S3 upon succesful read
putObject(req.file, buff, s3)
)
.then((results) => {
// build url of the resource upon successful insertion
const resourceURL = `https://${AWS_S3_BUCKET_NAME}.${AWS_S3_HOSTNAME}/${results}`;
const doc = {
comments,
title,
ts: new Date(),
image: resourceURL, // Your URL reference to image here
};
// Insert to your mongoDB
mongoClient
.db(MONGO_DB)
.collection(MONGO_COLLECTION)
.insertOne(doc)
.then((results) => {
// delete the temp file when no error from MONGO & AWS S3
fs.unlink(req.file.path, () => {});
// return the inserted object
res.status(200).json(results.ops[0]);
})
.catch((error) => {
console.error('Mongo insert error: ', error);
res.status(500);
res.json({ error });
});
})
.catch((error) => {
console.error('insert error: ', error);
res.status(500);
res.json({ error });
});
}