handler.js

'use strict';

const AWS = require('aws-sdk');
const rekognition = new AWS.Rekognition();
const s3 = new AWS.S3();

module.exports.validateImage = async (event) => {
  
  const s3Record = event.Records[0].s3;
  const bucket = s3Record.bucket.name;
  const key = s3Record.object.key;

  console.log(`A file named ${key} was put in a bucket ${bucket}`);

  // Detect the labels
  return detectLabels(bucket, key).then(labels => {
    console.log(labels);
    const isAHuman = checkIsHuman(labels);

    console.log(isAHuman);
    if (!isAHuman) {
      return removeImage(bucket, key).then(() => {
        console.log('The image was not a human and was removed');
        return;
      });
    }
  }).catch(error => {
    return error;
  })

};


//function part


function checkIsHuman(labels){
  return labels
  .map(label => {
    return label.Name === 'Human' ? true : false
  }).some( val => {
    return val === true;
  });
}

function detectLabels(bucket, key) {
  const params = {
    Image: {
     S3Object: {
      Bucket: bucket, 
      Name: key
     }
    }, 
    MaxLabels: 5, 
    MinConfidence: 85
   };

   return rekognition.detectLabels(params).promise().then(data => {
      return data.Labels;
   }).catch(error => {
     console.log(error);
     return error;
   });  
}

function checkIsACat(labels) {
  return labels
  .map(label => {
    return label.Name === 'Cat' ? true : false
  }).some( val => {
    return val === true;
  });
}

function removeImage(bucket, key) {
  const params = {
    Bucket: bucket, 
    Key: key
   };

   return s3.deleteObject(params).promise(); 
}