[gitalb-runner] AWS EC2 autoscale and a specific EBS volume

I use Autoscale AWS EC2 with docker+machine executor for my CI. I would like to attach to the runner a specific EBS volume (with some data which needs to persist between CI runs). I know there is a REX-Ray plugin that enables that. However, how to combine it with the gitlab-runner configuration? I guess in runners.machine section I would need to specify a script that would install and configure the plugin on the machine, so when the actual docker image is being launched, proper volume is bound (through volume in runners.docker). Unfortunately, I didn’t find such a possibility in runners.machine options.