Cannot upload image to s3 using serverless framework but it work in offline (buffer issue) - amazon-s3

Question

I'm trying to deploy a lambda function allowing me to upload a picture to S3.
The lambda works well in offline but when I'm deploy it to AWS, the function doesn't work.
The first error I encountered was this one :
ERROR (node:7) [DEP0005] DeprecationWarning: Buffer() is deprecated due to security and usability issues. Please use the Buffer.alloc(), Buffer.allocUnsafe(), or Buffer.from() methods instead.
So, I followed the recommendation to use Buffer.from() method instead. But it doesn't work too. The lambda run until the timeout.
Can someone tell me where I was wrong or suggest me another solution ?
Below my lambda function :
const AWS = require("aws-sdk");
const Busboy = require("busboy");
const uuidv4 = require("uuid/v4");
require("dotenv").config();
AWS.config.update({
accessKeyId: process.env.ACCESS_KEY_ID,
secretAccessKey: process.env.SECRET_ACCESS_KEY,
subregion: process.env.SUB_REGION
});
const s3 = new AWS.S3();
const getContentType = event => {
// see the second block of codes
};
const parser = event => {
// see the third block of codes
};
module.exports.main = (event, context, callback) => {
context.callbackWaitsForEmptyEventLoop = false;
const uuid = uuidv4();
const uploadFile = async (image, uuid) =>
new Promise(() => {
// const bitmap = new Buffer(image, "base64"); // <====== deprecated
const bitmap = Buffer.from(image, "base64"); // <======== problem here
const params = {
Bucket: "my_bucket",
Key: `${uuid}.jpeg`,
ACL: "public-read",
Body: bitmap,
ContentType: "image/jpeg"
};
s3.putObject(params, function(err, data) {
if (err) {
return callback(null, "ERROR");
}
return callback(null, "SUCCESS");
});
});
parser(event).then(() => {
uploadFile(event.body.file, uuid);
});
};
getContentType() :
const getContentType = event => {
const contentType = event.headers["content-type"];
if (!contentType) {
return event.headers["Content-Type"];
}
return contentType;
};
parser()
const parser = event =>
new Promise((resolve, reject) => {
const busboy = new Busboy({
headers: {
"content-type": getContentType(event)
}
});
const result = {};
busboy.on("file", (fieldname, file, filename, encoding, mimetype) => {
file.on("data", data => {
result.file = data;
});
file.on("end", () => {
result.filename = filename;
result.contentType = mimetype;
});
});
busboy.on("field", (fieldname, value) => {
result[fieldname] = value;
});
busboy.on("error", error => reject(error));
busboy.on("finish", () => {
event.body = result;
resolve(event);
});
busboy.write(event.body, event.isBase64Encoded ? "base64" : "binary");
busboy.end();
});

Answer 1

new Buffer(number) // Old
Buffer.alloc(number) // New
new Buffer(string) // Old
Buffer.from(string) // New
new Buffer(string, encoding) // Old
Buffer.from(string, encoding) // New
new Buffer(...arguments) // Old
Buffer.from(...arguments) // New

Answer 2

You are using callbackWaitsForEmptyEventLoop which basically let lambda function thinks that the work is not over yet. Also, you are wrapping it in promise but not resolving it. You can simplify this logic using following inbuilt promise function on aws-sdk
module.exports.main = async event => {
const uuid = uuidv4();
await parser(event); // not sure if this needs to be async or not. check
const bitmap = Buffer.from(event.body.file, "base64"); // <======== problem here
const params = {
Bucket: "my_bucket",
Key: `${uuid}.jpeg`,
ACL: "public-read",
Body: bitmap,
ContentType: "image/jpeg"
};
const response = await s3.putObject(params).promise();
return response;
};