upload files to aws s3 from node js - node.js

Question

I am using aws sdk to uplod user input image and then get the image link from aws and i will store the link in mongoDB. In that case when i run .upload() it is async.
const imgSRC = [];
for (let img of image) {
console.log(img);
const params = {
Bucket: process.env.AWS_BUCKET,
Key: `${img.originalname}_${userID}`,
Body: img.buffer,
};
s3.upload(params, (error, data) => {
if (error) {
console.log(error);
res.status(500).json({ msg: "server error" });
}
imgSRC.push(data.Location);
console.log(imgSRC);
});
}
const newPost = new Post({
userID: userID,
contentID: contentID,
posts: [
{
caption: caption,
data: imgSRC,
},
],
});
const post = await newPost.save();
in that case when the .save to mongodb run, there is no imgLinks from aws yet. How can i fix that things.
I've already tried async and it didn't work

Answer 1

You need to use Promise.all() in this manner
const uploadImage = (obj) => {
return new Promise((resolve, reject) => {
const params = {
Bucket: process.env.AWS_BUCKET,
Key: obj.key,
Body: obj.body,
}
s3.upload(params, (error, data) => {
if (error) {
console.log(error);
return reject(error);
}
return data;
});
})
}
const mainFunction = async () => {
const promises = [];
for (let img of image) {
const options = {
key: `${img.originalname}_${userID}`,
body: img.buffer
};
promises.push(uploadImage(options));
}
const result = await Promise.all(promises);
const imgSRC = result.map((r) => { return r.Location });
return imgSRC;
}

Answer 2

If you use await on s3.upload method you should remove the callback for this method.
try {
const data = await s3.upload(params);
imgSRC.push(data.Location);
console.log(imgSRC);
} catch(e) {
console.log(error);
res.status(500).json({ msg: "server error" });
}
Let me know if it works.