daemontools has the best philosophy for this in my opinion: just start the service. If the prerequisites are unavailable, the service will just terminate. I

daemontools has the best philosophy for this in my opinion: just start the service. If the prerequisites are unavailable, the service will just terminate. If that happens, wait one second, then try start again. It's perfect. No stupid 5 minute timeout like sysvinit, no stupid dependency management like systemd/upstart, very little to consider when adding new services. If you want to use it as your init.. just look into 'runit-init'. I've been using this for 4+ years, and it's fantastic.