It’s been a couple of years since I’ve last used it, but if you want container orchestration with a relatively small footprint, maybe Hashicorp Nomad (perhaps in conjunction with Consul and Traefik) is still an option. These were all single binary tools. I did not personally run them on 2G mem VPSes, but it might still be worthwhile for you to take a look.

It looks like Nomad has a driver to run software via isolated fork/exec, as well, in addition to Docker containers.