Make systemd notify optional in generic api server

To properly notify systemd that the k3s server is ready we need to
prevent the current k8s notification and add one to the k3s cli.

staging/src/k8s.io/apiserver/pkg/server/genericapiserver.go

@@ -44,6 +44,10 @@ import (
 	restclient "k8s.io/client-go/rest"
 )
 
+var (
+	NotifySystemD = true
+)
+
 // Info about an API group.
 type APIGroupInfo struct {
 	PrioritizedVersions []schema.GroupVersion
@@ -292,9 +296,11 @@ func (s preparedGenericAPIServer) NonBlockingRun(stopCh <-chan struct{}) error {
 
 	s.RunPostStartHooks(stopCh)
 
+	if NotifySystemD {
 		if _, err := systemd.SdNotify(true, "READY=1\n"); err != nil {
 			klog.Errorf("Unable to send systemd daemon successful start message: %v\n", err)
 		}
+	}
 
 	return nil
 }