failback to alternate drivers if startup fails with automatic choice

cmd/minikube/cmd/start.go

@@ -20,6 +20,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"math"
+	"math/rand"
 	"net"
 	"net/url"
 	"os"
@@ -304,11 +305,41 @@ func runStart(cmd *cobra.Command, args []string) {
 	}
 
 	validateSpecifiedDriver(existing)
-	ds, alts := selectDriver(existing)
+	ds, alts, specified := selectDriver(existing)
+	err = startWithDriver(cmd, ds, existing)
+	if err != nil {
+		if specified {
+			// User specified an invalid or broken driver
+			exit.WithCodeT(exit.Failure, "Startup with {{.driver}} driver failed: {{.error}}", out.V{"driver": ds.Name, "error": err})
+		}
+
+		// Walk down the rest of the options
+		for _, alt := range alts {
+			out.WarningT("Startup with {{.old_driver}} driver failed, trying with {{.new_driver}}.", out.V{"old_driver": ds.Name, "new_driver": alt.Name})
+			ds = alt
+			// Delete the existing cluster and try again with the next driver on the list
+			profile, err := config.LoadProfile(ClusterFlagValue())
+			if err != nil {
+				out.ErrT(out.Meh, `"{{.name}}" profile does not exist, trying anyways.`, out.V{"name": ClusterFlagValue()})
+			}
+
+			err = deleteProfile(profile)
+			if err != nil {
+				out.WarningT("Failed to delete cluster {{.name}}, proceeding with retry anyway.", out.V{"name": ClusterFlagValue()})
+			}
+			err = startWithDriver(cmd, ds, existing)
+			if err != nil {
+				continue
+			}
+		}
+	}
 
 }
 
 func startWithDriver(cmd *cobra.Command, ds registry.DriverState, existing *config.ClusterConfig) error {
+	if rand.Int()%2 == 0 {
+		return errors.New("OH NO RANDOM FAILURE")
+	}
 	driverName := ds.Name
 	glog.Infof("selected driver: %s", driverName)
 	validateDriver(ds, existing)
@@ -328,7 +359,7 @@ func startWithDriver(cmd *cobra.Command, ds registry.DriverState, existing *conf
 	k8sVersion := getKubernetesVersion(existing)
 	cc, n, err := generateCfgFromFlags(cmd, k8sVersion, driverName)
 	if err != nil {
-		exit.WithError("Failed to generate config", err)
+		return errors.Wrap(err, "Failed to generate config")
 	}
 
 	// This is about as far as we can go without overwriting config files
@@ -340,7 +371,7 @@ func startWithDriver(cmd *cobra.Command, ds registry.DriverState, existing *conf
 	if driver.IsVM(driverName) {
 		url, err := download.ISO(viper.GetStringSlice(isoURL), cmd.Flags().Changed(isoURL))
 		if err != nil {
-			exit.WithError("Failed to cache ISO", err)
+			return errors.Wrap(err, "Failed to cache ISO")
 		}
 		cc.MinikubeISO = url
 	}
@@ -361,7 +392,10 @@ func startWithDriver(cmd *cobra.Command, ds registry.DriverState, existing *conf
 
 	kubeconfig, err := node.Start(cc, n, existingAddons, true)
 	if err != nil {
-		kubeconfig = maybeDeleteAndRetry(cc, n, existingAddons, err)
+		kubeconfig, err = maybeDeleteAndRetry(cc, n, existingAddons, err)
+		if err != nil {
+			return err
+		}
 	}
 
 	numNodes := viper.GetInt(nodes)
@@ -383,7 +417,7 @@ func startWithDriver(cmd *cobra.Command, ds registry.DriverState, existing *conf
 				out.Ln("") // extra newline for clarity on the command line
 				err := node.Add(&cc, n)
 				if err != nil {
-					exit.WithError("adding node", err)
+					return errors.Wrap(err, "adding node")
 				}
 			}
 		}
@@ -468,9 +502,9 @@ func showKubectlInfo(kcs *kubeconfig.Settings, k8sVersion string, machineName st
 	return nil
 }
 
-func maybeDeleteAndRetry(cc config.ClusterConfig, n config.Node, existingAddons map[string]bool, originalErr error) *kubeconfig.Settings {
+func maybeDeleteAndRetry(cc config.ClusterConfig, n config.Node, existingAddons map[string]bool, originalErr error) (*kubeconfig.Settings, error) {
 	if viper.GetBool(deleteOnFailure) {
-		out.T(out.Warning, "Node {{.name}} failed to start, deleting and trying again.", out.V{"name": n.Name})
+		out.WarningT("Node {{.name}} failed to start, deleting and trying again.", out.V{"name": n.Name})
 		// Start failed, delete the cluster and try again
 		profile, err := config.LoadProfile(cc.Name)
 		if err != nil {
@@ -490,14 +524,13 @@ func maybeDeleteAndRetry(cc config.ClusterConfig, n config.Node, existingAddons
 			}
 			if err != nil {
 				// Ok we failed again, let's bail
-				exit.WithError("Start failed after cluster deletion", err)
+				return nil, err
 			}
 		}
-		return kubeconfig
+		return kubeconfig, nil
 	}
 	// Don't delete the cluster unless they ask
-	exit.WithError("startup failed", originalErr)
-	return nil
+	return nil, errors.Wrap(originalErr, "startup failed")
 }
 
 func kubectlVersion(path string) (string, error) {
@@ -525,7 +558,7 @@ func kubectlVersion(path string) (string, error) {
 	return cv.ClientVersion.GitVersion, nil
 }
 
-func selectDriver(existing *config.ClusterConfig) (registry.DriverState, []registry.DriverState) {
+func selectDriver(existing *config.ClusterConfig) (registry.DriverState, []registry.DriverState, bool) {
 	// Technically unrelated, but important to perform before detection
 	driver.SetLibvirtURI(viper.GetString(kvmQemuURI))
 
@@ -534,7 +567,7 @@ func selectDriver(existing *config.ClusterConfig) (registry.DriverState, []regis
 		old := hostDriver(existing)
 		ds := driver.Status(old)
 		out.T(out.Sparkle, `Using the {{.driver}} driver based on existing profile`, out.V{"driver": ds.String()})
-		return ds, nil
+		return ds, nil, true
 	}
 
 	// Default to looking at the new driver parameter
@@ -554,7 +587,7 @@ func selectDriver(existing *config.ClusterConfig) (registry.DriverState, []regis
 			exit.WithCodeT(exit.Unavailable, "The driver '{{.driver}}' is not supported on {{.os}}", out.V{"driver": d, "os": runtime.GOOS})
 		}
 		out.T(out.Sparkle, `Using the {{.driver}} driver based on user configuration`, out.V{"driver": ds.String()})
-		return ds, nil
+		return ds, nil, true
 	}
 
 	// Fallback to old driver parameter
@@ -564,7 +597,7 @@ func selectDriver(existing *config.ClusterConfig) (registry.DriverState, []regis
 			exit.WithCodeT(exit.Unavailable, "The driver '{{.driver}}' is not supported on {{.os}}", out.V{"driver": d, "os": runtime.GOOS})
 		}
 		out.T(out.Sparkle, `Using the {{.driver}} driver based on user configuration`, out.V{"driver": ds.String()})
-		return ds, nil
+		return ds, nil, true
 	}
 
 	pick, alts := driver.Suggest(driver.Choices(viper.GetBool("vm")))
@@ -581,7 +614,7 @@ func selectDriver(existing *config.ClusterConfig) (registry.DriverState, []regis
 	} else {
 		out.T(out.Sparkle, `Automatically selected the {{.driver}} driver`, out.V{"driver": pick.String()})
 	}
-	return pick, alts
+	return pick, alts, false
 }
 
 // hostDriver returns the actual driver used by a libmachine host, which can differ from our config

go.mod

@@ -82,6 +82,7 @@ require (
 	google.golang.org/genproto v0.0.0-20200117163144-32f20d992d24 // indirect
 	google.golang.org/grpc v1.26.0 // indirect
 	gopkg.in/mgo.v2 v2.0.0-20190816093944-a6b53ec6cb22 // indirect
+	gopkg.in/yaml.v2 v2.2.8
 	gotest.tools/v3 v3.0.2 // indirect
 	k8s.io/api v0.17.3
 	k8s.io/apimachinery v0.17.3

pkg/minikube/exit/exit.go

@@ -18,14 +18,11 @@ limitations under the License.
 package exit
 
 import (
-	"fmt"
 	"os"
 	"runtime"
 
-	"github.com/golang/glog"
 	"k8s.io/minikube/pkg/minikube/out"
 	"k8s.io/minikube/pkg/minikube/problem"
-	"k8s.io/minikube/pkg/minikube/translate"
 )
 
 // Exit codes based on sysexits(3)
@@ -40,9 +37,6 @@ const (
 	IO          = 74 // IO represents an I/O error
 	Config      = 78 // Config represents an unconfigured or misconfigured state
 	Permissions = 77 // Permissions represents a permissions error
-
-	// MaxLogEntries controls the number of log entries to show for each source
-	MaxLogEntries = 3
 )
 
 // UsageT outputs a templated usage error and exits with error code 64
@@ -63,7 +57,7 @@ func WithError(msg string, err error) {
 	if p != nil {
 		WithProblem(msg, err, p)
 	}
-	displayError(msg, err)
+	out.DisplayError(msg, err)
 	os.Exit(Software)
 }
 
@@ -79,29 +73,3 @@ func WithProblem(msg string, err error, p *problem.Problem) {
 	}
 	os.Exit(Config)
 }
-
-// WithLogEntries outputs an error along with any important log entries, and exits.
-func WithLogEntries(msg string, err error, entries map[string][]string) {
-	displayError(msg, err)
-
-	for name, lines := range entries {
-		out.T(out.FailureType, "Problems detected in {{.entry}}:", out.V{"entry": name})
-		if len(lines) > MaxLogEntries {
-			lines = lines[:MaxLogEntries]
-		}
-		for _, l := range lines {
-			out.T(out.LogEntry, l)
-		}
-	}
-	os.Exit(Software)
-}
-
-func displayError(msg string, err error) {
-	// use Warning because Error will display a duplicate message to stderr
-	glog.Warningf(fmt.Sprintf("%s: %v", msg, err))
-	out.ErrT(out.Empty, "")
-	out.FatalT("{{.msg}}: {{.err}}", out.V{"msg": translate.T(msg), "err": err})
-	out.ErrT(out.Empty, "")
-	out.ErrT(out.Sad, "minikube is exiting due to an error. If the above message is not useful, open an issue:")
-	out.ErrT(out.URL, "https://github.com/kubernetes/minikube/issues/new/choose")
-}

pkg/minikube/node/start.go

@@ -86,7 +86,7 @@ func Start(cc config.ClusterConfig, n config.Node, existingAddons map[string]boo
 	// Abstraction leakage alert: startHost requires the config to be saved, to satistfy pkg/provision/buildroot.
 	// Hence, saveConfig must be called before startHost, and again afterwards when we know the IP.
 	if err := config.SaveProfile(viper.GetString(config.ProfileName), &cc); err != nil {
-		exit.WithError("Failed to save config", err)
+		return nil, errors.Wrap(err, "Failed to save config")
 	}
 
 	handleDownloadOnly(&cacheGroup, &kicGroup, n.KubernetesVersion)
@@ -120,7 +120,8 @@ func Start(cc config.ClusterConfig, n config.Node, existingAddons map[string]boo
 		bs = setupKubeAdm(machineAPI, cc, n)
 		err = bs.StartCluster(cc)
 		if err != nil {
-			exit.WithLogEntries("Error starting cluster", err, logs.FindProblems(cr, bs, cc, mRunner))
+			out.LogEntries("Error starting cluster", err, logs.FindProblems(cr, bs, cc, mRunner))
+			return nil, err
 		}
 
 		// write the kubeconfig to the file system after everything required (like certs) are created by the bootstrapper

pkg/minikube/out/out.go

@@ -26,6 +26,7 @@ import (
 
 	"github.com/golang/glog"
 	isatty "github.com/mattn/go-isatty"
+	"k8s.io/minikube/pkg/minikube/translate"
 )
 
 // By design, this package uses global references to language and output objects, in preference
@@ -51,6 +52,9 @@ var (
 	OverrideEnv = "MINIKUBE_IN_STYLE"
 )
 
+// MaxLogEntries controls the number of log entries to show for each source
+const MaxLogEntries = 3
+
 // fdWriter is the subset of file.File that implements io.Writer and Fd()
 type fdWriter interface {
 	io.Writer
@@ -175,3 +179,29 @@ func wantsColor(fd uintptr) bool {
 	glog.Infof("isatty.IsTerminal(%d) = %v\n", fd, isT)
 	return isT
 }
+
+// LogEntries outputs an error along with any important log entries.
+func LogEntries(msg string, err error, entries map[string][]string) {
+	DisplayError(msg, err)
+
+	for name, lines := range entries {
+		T(FailureType, "Problems detected in {{.entry}}:", V{"entry": name})
+		if len(lines) > MaxLogEntries {
+			lines = lines[:MaxLogEntries]
+		}
+		for _, l := range lines {
+			T(LogEntry, l)
+		}
+	}
+}
+
+// DisplayError
+func DisplayError(msg string, err error) {
+	// use Warning because Error will display a duplicate message to stderr
+	glog.Warningf(fmt.Sprintf("%s: %v", msg, err))
+	ErrT(Empty, "")
+	FatalT("{{.msg}}: {{.err}}", V{"msg": translate.T(msg), "err": err})
+	ErrT(Empty, "")
+	ErrT(Sad, "minikube is exiting due to an error. If the above message is not useful, open an issue:")
+	ErrT(URL, "https://github.com/kubernetes/minikube/issues/new/choose")
+}