Smoothly retry host startup

pkg/minikube/node/start.go

@@ -320,14 +320,45 @@ func startMachine(cfg *config.ClusterConfig, node *config.Node) (runner command.
 }
 
 // startHost starts a new minikube host using a VM or None
-func startHost(api libmachine.API, mc config.ClusterConfig, n config.Node) (*host.Host, bool) {
-	host, exists, err := machine.StartHost(api, mc, n)
-	if err != nil {
-		exit.WithError("Unable to start VM. Please investigate and run 'minikube delete' if possible", err)
+func startHost(api libmachine.API, cc config.ClusterConfig, n config.Node) (*host.Host, bool) {
+	host, exists, err := machine.StartHost(api, cc, n)
+	if err == nil {
+		return host, exists
 	}
+	out.T(out.Embarrassed, "StartHost failed, but will try again: {{.error}}", out.V{"error": err})
+
+	// NOTE: People get very cranky if you delete their prexisting VM. Only delete new ones.
+	if !exists {
+		err := machine.DeleteHost(api, driver.MachineName(cc, n))
+		if err != nil {
+			glog.Warningf("delete host: %v", err)
+		}
+	}
+
+	// Try again, but just once to avoid copious error messages
+	time.Sleep(5 * time.Second)
+
+	host, exists, err = machine.StartHost(api, cc, n)
+	if err == nil {
+		return host, exists
+	}
+
+	out.T(out.FailureType, "StartHost failed again: {{.error}}", out.V{"error": err})
+	out.T(out.Workaround, `Run: "{{.cmd}} delete", then "{{.cmd}} start --alsologtostderr -v=1" to try again with more logs`,
+		out.V{"cmd": minikubeCmd()})
+
+	exit.WithError("Unable to start VM after repeated tries. Please try {{'minikube delete' if possible", err)
 	return host, exists
 }
 
+// Return a minikube command containing the current profile name
+func minikubeCmd() string {
+	if viper.GetString(config.ProfileName) != constants.DefaultClusterName {
+		return fmt.Sprintf("minikube -p %s", config.ProfileName)
+	}
+	return "minikube"
+}
+
 // validateNetwork tries to catch network problems as soon as possible
 func validateNetwork(h *host.Host, r command.Runner) string {
 	ip, err := h.Driver.GetIP()