Make it possible to recover from a previously aborted StartCluster (Ctrl-C)

cmd/minikube/cmd/start.go

@@ -1210,24 +1210,13 @@ func configureRuntimes(runner cruntime.CommandRunner, drvName string, k8s cfg.Ku
 
 // bootstrapCluster starts Kubernetes using the chosen bootstrapper
 func bootstrapCluster(bs bootstrapper.Bootstrapper, r cruntime.Manager, runner command.Runner, kc cfg.KubernetesConfig, preexisting bool, isUpgrade bool) {
-	// hum. bootstrapper.Bootstrapper should probably have a Name function.
-	bsName := viper.GetString(cmdcfg.Bootstrapper)
-
 	if isUpgrade || !preexisting {
 		out.T(out.Pulling, "Pulling images ...")
 		if err := bs.PullImages(kc); err != nil {
 			out.T(out.FailureType, "Unable to pull images, which may be OK: {{.error}}", out.V{"error": err})
 		}
 	}
 
-	if preexisting {
-		out.T(out.Restarting, "Relaunching Kubernetes using {{.bootstrapper}} ... ", out.V{"bootstrapper": bsName})
-		if err := bs.RestartCluster(kc); err != nil {
-			exit.WithLogEntries("Error restarting cluster", err, logs.FindProblems(r, bs, runner))
-		}
-		return
-	}
-
 	out.T(out.Launch, "Launching Kubernetes ... ")
 	if err := bs.StartCluster(kc); err != nil {
 		exit.WithLogEntries("Error starting cluster", err, logs.FindProblems(r, bs, runner))

pkg/minikube/bootstrapper/bootstrapper.go

@@ -39,7 +39,6 @@ type Bootstrapper interface {
 	PullImages(config.KubernetesConfig) error
 	StartCluster(config.KubernetesConfig) error
 	UpdateCluster(config.KubernetesConfig) error
-	RestartCluster(config.KubernetesConfig) error
 	DeleteCluster(config.KubernetesConfig) error
 	WaitForCluster(config.KubernetesConfig, time.Duration) error
 	// LogCommands returns a map of log type to a command which will display that log.

pkg/minikube/bootstrapper/kubeadm/kubeadm.go

@@ -94,6 +94,14 @@ var KubeadmExtraArgsWhitelist = map[int][]string{
 	},
 }
 
+// remote artifacts that must exist for minikube to function properly. The sign of a previously working installation.
+// NOTE: /etc is not persistent across restarts, so don't bother checking there
+var expectedArtifacts = []string{
+	"/var/lib/kubelet/kubeadm-flags.env",
+	"/var/lib/kubelet/config.yaml",
+	etcdDataDir(),
+}
+
 // yamlConfigPath is the path to the kubeadm configuration
 var yamlConfigPath = path.Join(vmpath.GuestEphemeralDir, "kubeadm.yaml")
 
@@ -222,8 +230,20 @@ func (k *Bootstrapper) createCompatSymlinks() error {
 	return nil
 }
 
+func (k *Bootstrapper) existingConfig() error {
+	args := append([]string{"ls"}, expectedArtifacts...)
+	_, err := k.c.RunCmd(exec.Command("sudo", args...))
+	return err
+}
+
 // StartCluster starts the cluster
 func (k *Bootstrapper) StartCluster(k8s config.KubernetesConfig) error {
+	err := k.existingConfig()
+	if err == nil {
+		return k.restartCluster(k8s)
+	}
+	glog.Infof("existence check: %v", err)
+
 	start := time.Now()
 	glog.Infof("StartCluster: %+v", k8s)
 	defer func() {
@@ -244,6 +264,7 @@ func (k *Bootstrapper) StartCluster(k8s config.KubernetesConfig) error {
 	ignore := []string{
 		fmt.Sprintf("DirAvailable-%s", strings.Replace(vmpath.GuestManifestsDir, "/", "-", -1)),
 		fmt.Sprintf("DirAvailable-%s", strings.Replace(vmpath.GuestPersistentDir, "/", "-", -1)),
+		fmt.Sprintf("DirAvailable-%s", strings.Replace(etcdDataDir(), "/", "-", -1)),
 		"FileAvailable--etc-kubernetes-manifests-kube-scheduler.yaml",
 		"FileAvailable--etc-kubernetes-manifests-kube-apiserver.yaml",
 		"FileAvailable--etc-kubernetes-manifests-kube-controller-manager.yaml",
@@ -281,6 +302,7 @@ func (k *Bootstrapper) StartCluster(k8s config.KubernetesConfig) error {
 	if err := k.adjustResourceLimits(); err != nil {
 		glog.Warningf("unable to adjust resource limits: %v", err)
 	}
+
 	return nil
 }
 
@@ -451,12 +473,13 @@ func (k *Bootstrapper) WaitForCluster(k8s config.KubernetesConfig, timeout time.
 	return k.waitForSystemPods(start, k8s, timeout)
 }
 
-// RestartCluster restarts the Kubernetes cluster configured by kubeadm
-func (k *Bootstrapper) RestartCluster(k8s config.KubernetesConfig) error {
-	glog.Infof("RestartCluster start")
+// restartCluster restarts the Kubernetes cluster configured by kubeadm
+func (k *Bootstrapper) restartCluster(k8s config.KubernetesConfig) error {
+	glog.Infof("restartCluster start")
+
 	start := time.Now()
 	defer func() {
-		glog.Infof("RestartCluster took %s", time.Since(start))
+		glog.Infof("restartCluster took %s", time.Since(start))
 	}()
 
 	version, err := parseKubernetesVersion(k8s.KubernetesVersion)
@@ -529,7 +552,7 @@ func (k *Bootstrapper) DeleteCluster(k8s config.KubernetesConfig) error {
 	return nil
 }
 
-// PullImages downloads images that will be used by RestartCluster
+// PullImages downloads images that will be used by Kubernetes
 func (k *Bootstrapper) PullImages(k8s config.KubernetesConfig) error {
 	version, err := parseKubernetesVersion(k8s.KubernetesVersion)
 	if err != nil {