Add Support for driver name alias

Author: sadlil

cmd/minikube/cmd/start.go

@@ -660,6 +660,12 @@ func validateSpecifiedDriver(existing *config.ClusterConfig) {
 		return
 	}
 
+	// hostDriver always returns original driver name even if an alias is used to start minikube.
+	// For all next start with alias needs to be check against the host driver aliases.
+	if driver.IsAlias(old, requested) {
+		return
+	}
+
 	exit.Advice(
 		reason.GuestDrvMismatch,
 		`The existing "{{.name}}" cluster was created using the "{{.old}}" driver, which is incompatible with requested "{{.new}}" driver.`,

pkg/minikube/driver/driver.go

@@ -53,6 +53,9 @@ const (
 	HyperV = "hyperv"
 	// Parallels driver
 	Parallels = "parallels"
+
+	// AliasKVM is driver name alias for kvm2
+	AliasKVM = "kvm"
 )
 
 var (
@@ -283,6 +286,17 @@ func Status(name string) registry.DriverState {
 	}
 }
 
+// IsAlias checks if an alias belongs to provided driver by name.
+func IsAlias(name, alias string) bool {
+	d := registry.Driver(name)
+	for _, da := range d.Alias {
+		if da == alias {
+			return true
+		}
+	}
+	return false
+}
+
 // SetLibvirtURI sets the URI to perform libvirt health checks against
 func SetLibvirtURI(v string) {
 	klog.Infof("Setting default libvirt URI to %s", v)

pkg/minikube/registry/drvs/kvm2/kvm2.go

@@ -43,6 +43,7 @@ const (
 func init() {
 	if err := registry.Register(registry.DriverDef{
 		Name:     driver.KVM2,
+		Alias:    []string{driver.AliasKVM},
 		Config:   configure,
 		Status:   status,
 		Priority: registry.Preferred,

pkg/minikube/registry/registry.go

@@ -86,6 +86,9 @@ type DriverDef struct {
 	// Name of the machine driver. It has to be unique.
 	Name string
 
+	// Alias contains a list of machine driver aliases. Each alias should also be unique.
+	Alias []string
+
 	// Config is a function that emits a configured driver struct
 	Config Configurator
 
@@ -109,13 +112,15 @@ func (d DriverDef) String() string {
 }
 
 type driverRegistry struct {
-	drivers map[string]DriverDef
-	lock    sync.RWMutex
+	drivers        map[string]DriverDef
+	driversByAlias map[string]DriverDef
+	lock           sync.RWMutex
 }
 
 func newRegistry() *driverRegistry {
 	return &driverRegistry{
-		drivers: make(map[string]DriverDef),
+		drivers:        make(map[string]DriverDef),
+		driversByAlias: make(map[string]DriverDef),
 	}
 }
 
@@ -129,6 +134,13 @@ func (r *driverRegistry) Register(def DriverDef) error {
 	}
 
 	r.drivers[def.Name] = def
+
+	for _, alias := range def.Alias {
+		if _, ok := r.driversByAlias[alias]; ok {
+			return fmt.Errorf("alias %q is already registered: %+v", alias, def)
+		}
+		r.driversByAlias[alias] = def
+	}
 	return nil
 }
 
@@ -150,5 +162,12 @@ func (r *driverRegistry) List() []DriverDef {
 func (r *driverRegistry) Driver(name string) DriverDef {
 	r.lock.RLock()
 	defer r.lock.RUnlock()
-	return r.drivers[name]
+
+	def, ok := r.drivers[name]
+	if ok {
+		return def
+	}
+
+	// Check if we have driver def with name as alias
+	return r.driversByAlias[name]
 }

pkg/minikube/registry/registry_test.go

@@ -63,3 +63,31 @@ func TestList(t *testing.T) {
 		t.Errorf("list mismatch (-want +got):\n%s", diff)
 	}
 }
+
+func TestDriverAlias(t *testing.T) {
+	foo := DriverDef{Name: "foo", Alias: []string{"foo-alias"}}
+	r := newRegistry()
+
+	if err := r.Register(foo); err != nil {
+		t.Errorf("Register = %v, expected nil", err)
+	}
+
+	d := r.Driver("foo")
+	if d.Empty() {
+		t.Errorf("driver.Empty = true, expected false")
+	}
+
+	d = r.Driver("foo-alias")
+	if d.Empty() {
+		t.Errorf("driver.Empty = true, expected false")
+	}
+
+	if diff := cmp.Diff(r.List(), []DriverDef{foo}); diff != "" {
+		t.Errorf("list mismatch (-want +got):\n%s", diff)
+	}
+
+	d = r.Driver("bar")
+	if !d.Empty() {
+		t.Errorf("driver.Empty = false, expected true")
+	}
+}