Custom System Services
You can also create your own system service in Docker Compose format. After creating your own custom service, you can launch it in RancherOS in a couple of methods. The service could be directly added to the cloud-config, or a docker-compose.yml file could be saved at a http(s) url location or in a specific directory of RancherOS.
https://rancher.com/docs/os/v1.x/en/system-services/custom-system-services/