I have a Dropwizard based application running on GKE. I'm already collecting lots of application specific metrics using dropwizard metrics support.

I know it can report metrics via HTTP, JMX, CSV, collectd, etc.

I want to send these metrics to Stackdriver.

Three alternatives came to mind:

1. build a new metric reporter using Stackdriver Monitoring API
2. create a new Stackdriver monitoring agent flavor
3. create a sidecar container that collects metrics (shared file or http polling) and send them to StackDriver (API ? collectd ?)

What would be the most efficient and straighforward way to achieve that ? Any help is appreciated.