import os

def download_code(event, context):
    """
    Download the runtime environment of a lambda to a given s3 bucket.
    """
    os.system("/bin/tar -zcvf /tmp/code.tar.gz /var/runtime/")
    with open("/tmp/code.tar.gz", "rb") as code:
        s3.upload_fileobj(code, event['bucket_name'], 'code.tar.gz')