Required procedure:

1. Someone does an upload to an S3 bucket.
2. This triggers a Lambda function that does some processing on the uploaded file(s).
3. Processed objects are now copied into a "processed" folder within the same bucket.

The copy-operation in Step 3 should never re-trigger the initial Lambda function itself.
I know that the general guidance is to use a different bucket for storing the processed objects in a situation like this (but this is not possible in this case).

So my approach was to set up the S3 trigger to only listen to PUT/POST-Method and excluded the COPY-Method. The lambda function itself uses python-boto (S3_CLIENT.copy_object(..)). The approach seems to work (the lambda function seems to not be retriggered by the copy operation)

However I wanted to ask if this approach is really reliable - is it?

CodePudding user response：

You can filter which events trigger the S3 notification.

There are 2 ways to trigger lambda from S3 event in general: bucket notifications and EventBridge.

Notifications: