s3dynamo.js

const AWS = require('aws-sdk')
const s3 = new AWS.S3()
const dynamodb = new AWS.DynamoDB()

exports.handler = (event, context, callback) => {
  fetchS3()
    .then(data => {
      console.log(data)
      return putDynamoDB(data.LastModified.toString())
    })
    .then(data => {
      console.log(data)

      const result = {
        "isBase64Encoded": false,
        "statusCode": 200,
        "headers": {},
        "body": "done"
      }

      callback(null, result);
    })
};


function fetchS3 (cb) {
  return new Promise((resolve, reject) => {
    const params = {
      Bucket: 'staging.vamp.io',
      Key: 'img/006-mock-ups/VAMP-light-laptop-v091-hero.png'
    }
    s3.getObject(params, (err, data) =>{
      if (err) return reject(err)
      resolve(data)  
    })
  })
}

function putDynamoDB (msg) {
  return new Promise((resolve, reject) => {
    const params = {
      Item: {
       "message": {
         S: msg
        }
      }, 
      TableName: "loadtestlambda"
     };

     dynamodb.putItem(params, (err, data) => {
      if (err) return reject(err)
      resolve(data)  
     })
  })
}