Node/Express/MongoDB app: uploading multiple images using Multer and Cloudinary - node.js

Question

hope someone can help me with this:
I am working on a Node/Express/Mongo CRUD app where every post/document has ONE image. I am using multer and cloudinary for uploading the images. However, I want users to be able to upload multiple images to each post. Ideally, the image urls/paths and IDs would be stored in arrays in my database.
I have been trying and researching for hours now but cannot seem to make it work, and there is no tutorial out there explaining how this (simple) task can be achieved using multer and cloudinary.
This is the code I am using to upload ONE image per post, which is working:
// CREATE Route - add new post to DB
router.post("/", middleware.isLoggedIn, upload.single('image'), function(req, res) {
cloudinary.v2.uploader.upload(req.file.path, function(err, result) {
if(err) {
req.flash('error', err.message);
return res.redirect('back');
};
// add cloudinary url for the image to the post object under image property
req.body.post.image = result.secure_url;
// add image's public_id to post object
req.body.post.imageId = result.public_id;
// add author to post
req.body.post.author = {
id: req.user._id,
username: req.user.username
}
Post.create(req.body.post, function(err, post) {
if (err) {
req.flash('error', err.message);
return res.redirect('back');
}
res.redirect('/posts/' + post.id);
});
});
});
How would I need to change this code in order to achieve this goal?
Thanks in advance for your help!

Answer 1

The upload API currently only supports a single file upload at a time, it does have a high concurrency rate (of about 40-50 concurrent calls) so you can use multi-threads to upload many files at once.
You can also use asynchronous calls, and tell Cloudinary to do the upload in the background by adding the async parameter and setting it to true.