Mount etcd data directory to host

cmd/kubeadm/app/kubeadm.go

@@ -42,6 +42,7 @@ func getEnvParams() map[string]string {
 	envParams := map[string]string{
 		"prefix":             globalPrefix,
 		"host_pki_path":      path.Join(globalPrefix, "pki"),
+		"host_etcd_path":     "/var/lib/etcd",
 		"hyperkube_image":    "",
 		"discovery_image":    "dgoodwin/kubediscovery:latest", // TODO(phase1): fmt.Sprintf("gcr.io/google_containers/kube-discovery-%s:%s", runtime.GOARCH, "1.0"),
 		"etcd_image":         "",

pkg/kubeadm/master/manifests.go

@@ -63,11 +63,12 @@ func WriteStaticPodManifests(s *kubeadmapi.KubeadmConfig) error {
 				"--advertise-client-urls=http://127.0.0.1:2379",
 				"--data-dir=/var/etcd/data",
 			},
+			VolumeMounts:  []api.VolumeMount{etcdVolumeMount()},
 			Image:         images.GetCoreImage(images.KubeEtcdImage, s.EnvParams["etcd_image"]),
 			LivenessProbe: componentProbe(2379, "/health"),
 			Name:          etcd,
 			Resources:     componentResources("200m"),
-		}),
+		}, etcdVolume(s)),
 		// TODO bind-mount certs in
 		kubeAPIServer: componentPod(api.Container{
 			Name:          kubeAPIServer,
@@ -111,6 +112,22 @@ func WriteStaticPodManifests(s *kubeadmapi.KubeadmConfig) error {
 	return nil
 }
 
+func etcdVolume(s *kubeadmapi.KubeadmConfig) api.Volume {
+	return api.Volume{
+		Name: "etcd",
+		VolumeSource: api.VolumeSource{
+			HostPath: &api.HostPathVolumeSource{Path: s.EnvParams["host_etcd_path"]},
+		},
+	}
+}
+
+func etcdVolumeMount() api.VolumeMount {
+	return api.VolumeMount{
+		Name:      "etcd",
+		MountPath: "/var/etcd",
+	}
+}
+
 func pkiVolume(s *kubeadmapi.KubeadmConfig) api.Volume {
 	return api.Volume{
 		Name: "pki",