{ fetchurl }: let version = "1.2.1"; in fetchurl { url = "https://logstash.objects.dreamhost.com/release/logstash-${version}-flatjar.jar"; name = "logstash-${version}.jar"; sha256 = "08zfhq6klhkqapqnyzbdikgryd8bj2fp0wdb5d6dawdan5psbf6h"; }