none driver: support non systemd ways to restart docker

[medyagh]

currently if u run none driver on a system that does have docker but it is not systemd
it wont work !

because we expect docker restart to use systemctl (and init.d scripts wont work)

// Restart restarts Docker on a host
func (r *Docker) Restart() error {
	c := exec.Command("sudo", "systemctl", "restart", "docker")
	if _, err := r.Runner.RunCmd(c); err != nil {
		return errors.Wrap(err, "restarting docker.")
	}
	return nil
}

https://github.com/kubernetes/minikube/blob/master/pkg/minikube/cruntime/docker.go#L101

we could try do restart docker service using "service restart docker" if there is no systemctl service file for docker.

[afbjorklund]

we could try do restart docker service using "service restart docker" if there is no systemctl service file for docker.

sound good, if not running systemd then service should be available (or easy enough to add).

This issue applies to all the runtimes, not only docker. It is also used for the kubelet, for example.

So the functionality (start/stop/restart/is-active) should probably move into some library functions ?

[afbjorklund]

Apparently last one needs LSB status_of_proc https://wiki.debian.org/LSBInitScripts/StatusSupport

[afbjorklund]

@medyagh : do we have any supported environments remaining, that don't use systemd ?

it used to be mostly for the older versions of ubuntu, used when travis used containers not vms

[sayboras]

I tried to run integration test with ubuntu docker (as I am developing in Mac). Then came across this issue as https://hub.docker.com/_/ubuntu 18.04 is running with service only.

Understand that running docker in docker is not ideal, but having VM is just too much for my 13' mac.

[afbjorklund]

@sayboras : we have the "docker" driver for that, running the VM tests in docker won't be enough

this basically means running only the unit tests locally, and rely on the CI infrastructure for the rest