s3 to dynamodb

index.js

const AWS = require('aws-sdk');
const docClient = new AWS.DynamoDB.DocumentClient();
const parseS3Event = require('./parse-s3-event');
const TABLE_NAME = process.env.TABLE_NAME;

exports.handler = (event) => {
    let S3Objects = parseS3Event(event);
    return Promise.all(S3Objects.map(saveToDynamoDB));
};

saveToDynamoDB = (data) => {
    if (!data) {
        return Promise.resolve();
    }
    let params = {
        TableName: TABLE_NAME,
        Item: {
            'title' : data.key,
            'author' : 'upload',
            'genre' : 'ebook',
            'price' :  'free'
          }
    }
    return docClient.put(params)
        .promise()
        .then(response => response)
        .catch(err => {
            console.log(err);
            return err;
        });
};

parse-s3-event.js

module.exports = (event) => {
	if (!event || !event.Records || !Array.isArray(event.Records)) {
		return [];
  }
  let extractMessage = record => record.s3 && record.s3.object;
	return event.Records.map(extractMessage).filter(object => object);
};

uploadEbook.yaml

AWSTemplateFormatVersion: '2010-09-09'
Transform: 'AWS::Serverless-2016-10-31'
Description: An AWS Serverless Specification template describing your function.
Resources:
  uploadEbook:
    Type: 'AWS::Serverless::Function'
    Properties:
      Handler: index.handler
      Runtime: nodejs8.10
      CodeUri: .
      Description: ''
      MemorySize: 128
      Timeout: 3
      Role: 'arn:aws:iam::294235872584:role/service-role/DynamoDBCrudPolicy'
      Events:
        BucketEvent1:
          Type: S3
          Properties:
            Bucket:
              Ref: Bucket1
            Events:
              - 's3:ObjectCreated:*'
      Environment:
        Variables:
          TABLE_NAME: book_table
  Bucket1:
    Type: 'AWS::S3::Bucket'