### Is there an existing issue for this?

- [X] I have searched the existing issues

### Feature description

Basically we want to only run the lambda when an insert is occurring in DynamoDB.
I tested using Dynobase deleting a record and the lambda still triggered.

```
resource "aws_lambda_event_source_mapping" "event-log" {
	event_source_arn  = aws_dynamodb_table.event-log.stream_arn
	function_name     = module.main.lambda-arn
	starting_position = "LATEST"
	enabled = true # change to false when truncating the table in localstack
	maximum_retry_attempts = 1 # limit retry on failure to 1 for now

	# https://dev.to/aws-builders/filtering-dynamodb-streams-before-lambda-p5p
	filter_criteria { # Doesn't seem to work on LocalStack for now
		filter {
			pattern = jsonencode({
				body = {
					eventName : ["INSERT"]
				}
			})
		}
	}
}
```


### 🧑‍💻 Implementation

_No response_

### Anything else?

 https://dev.to/aws-builders/filtering-dynamodb-streams-before-lambda-p5p
if not mapped:
        return False
    if not searched or mapped == searched:
        return True
    
    
    
    
    
    
    if re.match(r"^%s$" % searched, mapped):
        return True
    if mapped.startswith(searched):
        suffix = mapped[len(searched) :]
        return suffix[0] == "/"
    return False
def error_response(msg, code=500, error_type="InternalFailure"):
    if code != 404:
        LOG.debug(msg)
    return flask_error_response_json(msg, code=code, error_type=error_type)
def generate_lambda_arn(
    account_id: int, region: str, fn_name: str, qualifier: Optional[str] = None
):
    if qualifier:
        return f"arn:aws:lambda:{region}:{account_id}:function:{fn_name}:{qualifier}"
    else:
        return f"arn:aws:lambda:{region}:{account_id}:function:{fn_name}"