expStr:      []string{"FileContent--proc-sys-net-ipv4-ip_forward", "FileContent--proc-sys-net-ipv6-conf-default-forwarding"},
		},
		{
			testName:    "single stack ipv4",
			PodSubnet:   "10.244.0.0/16",
			serviceCidr: "10.96.0.0/16",
			expStr:      []string{"FileContent--proc-sys-net-ipv4-ip_forward"},
		},
		{
			testName:    "single stack ipv6",

	"k8s.io/kubernetes/cmd/kubeadm/app/images"
	"k8s.io/kubernetes/cmd/kubeadm/app/util/initsystem"
	utilruntime "k8s.io/kubernetes/cmd/kubeadm/app/util/runtime"
)

const (
	ipv4Forward                 = "/proc/sys/net/ipv4/ip_forward"
	ipv6DefaultForwarding       = "/proc/sys/net/ipv6/conf/default/forwarding"
	externalEtcdRequestTimeout  = 10 * time.Second
	externalEtcdRequestRetries  = 3
	externalEtcdRequestInterval = 5 * time.Second
)

var (