dynamodb-replication.py

import boto3
import copy
table = "${destTableName}"
def handler(event, context):
  // do some assume role stuff into another account here
  // client = boto3.client('iam')
  // response = client.assume_role(
  //    RoleArn=arn,
  //    RoleSessionName=username,
  //    DurationSeconds=timeout
  // )
  // boto3.client(
  //   service_name=service,
  //   aws_access_key_id=response['Credentials']['AccessKeyId'],
  //   aws_secret_access_key=response['Credentials']['SecretAccessKey'],
  //   aws_session_token=response['Credentials']['SessionToken'],
  //   region_name=region
  // )
  ddb = boto3.client('dynamodb')
  for record in event['Records']:
    try:
      data = record['dynamodb']
      newdata = copy.deepcopy(data)
      args = {
        'TableName': table,
        'Key': data['Keys']
      }
      if record['eventName'] in ['INSERT', 'MODIFY']:
        for k, v in data['NewImage'].items():
          newdata['NewImage'][k] = {}
          newdata['NewImage'][k]['Action'] = 'PUT'
          newdata['NewImage'][k]['Value'] = v
          if k in data['Keys']:
              del newdata['NewImage'][k]
        args['AttributeUpdates'] = newdata['NewImage']
        ddb.update_item(**args)
      elif record['eventName'] == 'REMOVE':
        ddb.delete_item(**args)
    except Exception as e:
      print(event)
      print(f'Exception: {e}')