S3

All S3 functions supports the config field roleArn to be able to assume a different role.

o.flatMap (
    s3.download (
        roleArn: 'the_role_arn_to_assume')
    )

S3 Download / Get

Download to filesystem

I.e, an S3 event that you receive from an AWS Lambda will contain the bucket and key to that file so downloading this locally is simple. The sample below will download it as a temp file on local disk and add the field ‘s3_download_path’ to the event.

observable.flatMap (
        s3.download (
            bucket: '{bucket_name}',
            key: '{key}',
            remove: true,
            output_field: 's3_download_path' // Optional, defaults to s3_download_path
        )
    ).doOnNext(console.stdout('File downloaded with filename {s3_download_path}'))

Download as BytesEvent

Similar to the example above but instead a BytesEvent with the complete contents of the S3 file is downloaded.

observable.flatMap (
        s3.get (
            bucket: '{bucket_name}',
            key: '{key}',
            codec: Codecs.BYTES // Optional, defaults to bytes
        )
    ).doOnNext{Event e -> println 'Size in bytes: ' + e.raw().size()}

S3 Put

S3 Put takes a reference to a file and puts it on S3. The example below takes the downloaded file and makes a copy with the appended suffix ‘.copy’.

.flatMap (
        s3.put (
            bucket: '{bucket}',
            key   : '{key}.copy',
            file  : '{s3_download_path}'
        )
    )