Hi folks. I need to update bucket if it exists and create bucket if it do not exists. I have been banging my head for a while but was not able to make any progress

import pulumi
import pulumi_aws as aws


existing_bucket = aws.s3.get_bucket(bucket="my-bucket")


modified_or_new_bucket = aws.s3.Bucket(
    "997911f256644644a1cc1c6d93d75e4fer",
    bucket="my-bucket",
    acl="private",
    opts=pulumi.ResourceOptions(import_=existing_bucket.id),
)

pulumi.export("Bucket", modified_or_new_bucket.arn)

This throws an error if bucket is not present. which is valid. but how to deal with this scenario

The best pattern for this is to import the bucket and manage it. In most cases, your code doesn't need to distinguish between exists and not-exists; you do that when starting to manage your environment. Pulumi can then take over and ensure everything continues to exist thereafter.