Upload a large file to aws s3 using multipart uploads

s3-multipart.js

// npm i --save dotenv aws-sdk

const dotenv = require('dotenv')
const path = require('path')
const fs = require('fs')
const AWS = require('aws-sdk');

dotenv.config({
    path: path.join(__dirname, '.env'),
    debug: true,
})

const S3 = new AWS.S3({
    apiVersion: '2006-03-01',
    accessKeyId: process.env.AWS_ACCESS_KEY_ID,
    secretAccessKey: process.env.AWS_SECRET_ACCESS_KEY,
    region: process.env.AWS_DEFAULT_REGION,
});

(async () => {
    let multipartCreateResult = await S3.createMultipartUpload({
        Bucket: process.env.BUCKET,
        Key: "movie.mp4",
        ACL: "public-read",
        ContentType: "video/mp4",
        StorageClass: 'STANDARD'
    }).promise()

    console.log("multipartCreateResult", multipartCreateResult)
    // process.exit(0)


    const CHUNK_SIZE = 10 * 1024 * 1024, // 10MB
        buffer = Buffer.alloc(CHUNK_SIZE),
        filePath = 'movie.mp4';

    let chunkCount = 1;
    let uploadPartResults = []
    fs.open(filePath, 'r', function (err, fd) {
        if (err) throw err;
        function readNextChunk() {
            fs.read(fd, buffer, 0, CHUNK_SIZE, null, async function (err, nread) {
                if (err) throw err;

                if (nread === 0) {
                    // done reading file, do any necessary finalization steps
                    console.log("uploadPartResults", uploadPartResults)
                    let completeUploadResponce = await S3.completeMultipartUpload({
                        Bucket: process.env.BUCKET,
                        Key: "movie.mp4",
                        MultipartUpload: {
                            Parts: uploadPartResults
                        },
                        UploadId: multipartCreateResult.UploadId
                    }).promise()

                    console.log("completeUploadResponce", completeUploadResponce)

                    fs.close(fd, function (err) {
                        if (err) throw err;
                    });
                    return;
                }

                var data;
                if (nread < CHUNK_SIZE) {
                    data = buffer.slice(0, nread);
                }
                else {
                    data = buffer;
                }

                // do something with `data`, then call `readNextChunk();`
                // console.log("chunkCount: ", chunkCount)
                let uploadPromiseResult = await S3.uploadPart({
                    Body: data,
                    Bucket: process.env.BUCKET,
                    Key: "movie.mp4",
                    PartNumber: chunkCount,
                    UploadId: multipartCreateResult.UploadId,
                }).promise()
                    .catch(err => {
                        console.log(err)
                    })
                console.log(`uploadPromiseResult - ${chunkCount}`, uploadPromiseResult)
                uploadPartResults.push({
                    PartNumber: chunkCount,
                    ETag: uploadPromiseResult.ETag
                })
                chunkCount++;
                readNextChunk()
            });
        }
        readNextChunk();
    });
})()