deduplication.py

import boto3
import time

def message_deduplication(message):
    alerthash = hashlib.md5(message.encode())
    ttl = str(int(time.time()+600))

    dynamodbclient = boto3.client('dynamodb')
    response = dynamodbclient.get_item(
        Key={
            'alerthash': {
                'S': alerthash.hexdigest(),
            }
        },
        TableName='deduplicationtab',
    )
    try:
        found = response['Item']
        if int(found['ttl']['N']) > int(time.time()) :
            print("Found message hash in DB")
            return True
    except KeyError:
        pass

    response = dynamodbclient.put_item(
        Item={
            'alerthash': {
                'S': alerthash.hexdigest(),
            },
            'ttl': {
                'N': ttl,
            }
        },
        TableName='deduplicationtab',
    )
    return False

 
def lambda_handler(event, context):
  #[...]
  if message_deduplication(message):
      return
  #[...]