Bug: There is no sequencer property in S3 LifecycleTransition event

[DKurilo]

Expected Behaviour

Parsed s3 event when parsing LifecycleTransition event

Current Behaviour

Parsing error. Actually for LifecycleTransition I see many errors.

Code snippet

import json

from aws_lambda_powertools.utilities.parser import parse
from aws_lambda_powertools.utilities.parser.models import S3RecordModel

def main():
    event = '{"eventVersion":"2.3","eventSource":"aws:s3","awsRegion":"us-east-1","eventTime":"2025-02-21T21:46:45.775Z","eventName":"LifecycleTransition","userIdentity":{"principalId":"s3.amazonaws.com"},"requestParameters":{"sourceIPAddress":"s3.amazonaws.com"},"responseElements":{"x-amz-request-id":"something-1","x-amz-id-2":"something-2"},"s3":{"s3SchemaVersion":"1.0","configurationId":"some-sns","bucket":{"name":"bucket-name","ownerIdentity":{"principalId":"PRICIPAL"},"arn":"arn:aws:s3:::bucket-name"},"object":{"key":"/path/to/file.parquet","size":12345,"eTag":"abcdef1232423423","versionId":"SomeThingThere"}},"lifecycleEventData":{"transitionEventData":{"destinationStorageClass":"INTELLIGENT_TIERING"}}}'
    print(str(parse(event=json.loads(event), model=S3RecordModel)))

if __name__ == "__main__":
    main()

Possible Solution

This line
https://github.com/aws-powertools/powertools-lambda-python/blob/develop/aws_lambda_powertools/utilities/parser/models/s3.py#L26
can be:

    sourceIPAddress: Union[IPvAnyNetwork, Literal["s3.amazonaws.com"]]

and this line:
https://github.com/aws-powertools/powertools-lambda-python/blob/develop/aws_lambda_powertools/utilities/parser/models/s3.py#L48

    sequencer: Optional[str] = None

Steps to Reproduce

Copy code snippet and run it.

Powertools for AWS Lambda (Python) version

latest

AWS Lambda function runtime

3.9

Packaging format used

PyPi

Debugging logs

[leandrodamascena]

Hi @DKurilo! Thanks for opening this issue and reporting this bug! I can confirm that the value of sourceIPAddress can be an IP or s3.amazonaws.com and we are missing that. Also, for the sequencer, this is only expected for events that create objects (PUTs) and delete objects and not for lifecycle events.

Do you want to submit a PR to fix this?

[DKurilo]

Hi @leandrodamascena ,
Sure, I'll do it today later.
Do you want me to add validator for sequencer?

[leandrodamascena]

Hey @DKurilo! I don't think we need a validator since there are many variations of eventName, and we might miss something, leading to another bug. Making it Optional, as you suggested, should be sufficient.

I'm assigning this issue to you! Thanks.

[DKurilo]

Here is PR: #6154

[github-actions]

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