upload_to_s3.ts

import * as fs from "fs";
import * as AWS from "aws-sdk";

const BUCKET_NAME = "<<bucket name>>";
const IAM_USER_KEY = "<<user key>>";
const IAM_USER_SECRET = "<<user secret>>";

const s3bucket = new AWS.S3({
  accessKeyId: IAM_USER_KEY,
  secretAccessKey: IAM_USER_SECRET
});

export function uploadToS3(fileName: string): Promise<any> {
  const readStream = fs.createReadStream(fileName);

  const params = {
    Bucket: BUCKET_NAME,
    Key: "myapp" + "/" + fileName,
    Body: readStream
  };

  return new Promise((resolve, reject) => {
    s3bucket.upload(params, function(err, data) {
      readStream.destroy();
      
      if (err) {
        return reject(err);
      }
      
      return resolve(data);
    });
  });
}