AWS Lambda function that creates metadata about a file uploaded to S3, and inserts this metadata into DynamoDB.

lambda_function.py

import json
import urllib.parse
import boto3


s3 = boto3.client('s3')
dynamodb_client = boto3.resource('dynamodb')

table_name = # your dynamodb table name
table = dynamodb_client.Table(table_name)


def lambda_handler(event, context):

    # Get the object from the event and show its content type
    bucket = event['Records'][0]['s3']['bucket']['name']
    key = urllib.parse.unquote_plus(event['Records'][0]['s3']['object']['key'], encoding='utf-8')
    timestamp = event['Records'][0]['eventTime']
    size = event['Records'][0]['s3']['object']['size']
    
    try:
        table.put_item(Item = {
            'filename': key,
            'bucket': bucket,
            'timestamp': timestamp,
            'size': size
        })
        
        return "Dynamodb insert a success for file {}".format(key)
        
    except Exception as e:
        print('Error getting object {} from bucket {}. Make sure they exist and your bucket is in the same region as this function.'.format(key, bucket))
        raise e