How to pass custom options for etcd-snapshot service?

Hi,
I have a k8s cluster running rancher HA; the cluster was setup with rke.

Per this page:

https://rancher.com/docs/rke/latest/en/etcd-snapshots/recurring-snapshots/

it states:

you can enable the etcd-snapshot service with [extra configuration options](https://rancher.com/docs/rke/latest/en/etcd-snapshots/recurring-snapshots/#options-for-the-etcd-snapshot-service)

I do see that the etcd-rolling-snapshots container is properly functioning, as there are rolling snapshots in the node directory /opt/rke/etcd-snapshots.

In what context is ‘service’ defined? How do I properly pass custom options to the ‘etcd-snapshot’ service?

To apply these options I modified the service definition in the cluster.yml file per the service example at the bottom of the page, and then ran:

$ rke up --config cluster.yml

…to apply the modified service to the cluster. Looks like it is setting up for uploading the snapshots to S3, so I think we’re in business:

$ docker logs etcd-rolling-snapshots
time="2020-02-05T21:56:00Z" level=info msg="invoking set s3 service client"
...