S3 Event Prefix for Subfolders

Question

I set up an event listener on S3 that fires to a lambda function for ObjectCreate events. The S3 bucket considered has a subfolder dev/subfolder-a/ and we would like to only listen to new objects created under dev/subfolder-a/.

We tried setting up the prefix as dev/subfolder-a/ on the event notification, but the events never fire when we upload new files in subfolder-a

Now if we change the prefix to simply dev/, we receive the events but contains new uploaded files in all other subfolders (say dev/subfolder-b/ and dev/subfolder-c/).

How can we specify a prefix for an S3 event notification to only consider events happening in a specific subfolder (or even sub-subfolders)?

Answer 1

Are you sure the upload to dev/subfolder-a/ is successful? Documentation states that:-

You will not receive event notifications from failed operations.

I just tested your workflow in the AWS Console (only difference is that my event is pushed to test SQS queue) and through some code and it worked as expected.