--kubernetes-version: assume latest patch version if not specified by user

cmd/minikube/cmd/start.go

@@ -88,6 +88,9 @@ type versionJSON struct {
 	Commit          string `json:"commit"`
 }
 
+// ErrKubernetesPatchNotFound is when a patch was not found for the given <major>.<minor> version
+var ErrKubernetesPatchNotFound = errors.New("Unable to detect the latest patch release for specified Kubernetes version")
+
 var (
 	registryMirror   []string
 	insecureRegistry []string
@@ -318,7 +321,10 @@ func provisionWithDriver(cmd *cobra.Command, ds registry.DriverState, existing *
 		stopk8s = true
 	}
 
-	k8sVersion := getKubernetesVersion(existing)
+	k8sVersion, err := getKubernetesVersion(existing)
+	if err != nil {
+		klog.Warningf("failed getting Kubernetes version: %v", err)
+	}
 	rtime := getContainerRuntime(existing)
 	cc, n, err := generateClusterConfig(cmd, existing, k8sVersion, rtime, driverName)
 	if err != nil {
@@ -1585,17 +1591,24 @@ func createNode(cc config.ClusterConfig, existing *config.ClusterConfig) (config
 	// Create the initial node, which will necessarily be a control plane
 	if existing != nil {
 		cp, err := config.PrimaryControlPlane(existing)
-		cp.KubernetesVersion = getKubernetesVersion(&cc)
-		cp.ContainerRuntime = getContainerRuntime(&cc)
 		if err != nil {
 			return cc, config.Node{}, err
 		}
+		newVer, err := getKubernetesVersion(&cc)
+		cp.KubernetesVersion = newVer
+		if err != nil {
+			klog.Warningf("failed getting Kubernetes version: %v", err)
+		}
+		cp.ContainerRuntime = getContainerRuntime(&cc)
 
 		// Make sure that existing nodes honor if KubernetesVersion gets specified on restart
 		// KubernetesVersion is the only attribute that the user can override in the Node object
 		nodes := []config.Node{}
 		for _, n := range existing.Nodes {
-			n.KubernetesVersion = getKubernetesVersion(&cc)
+			n.KubernetesVersion, err = getKubernetesVersion(&cc)
+			if err != nil {
+				klog.Warningf("failed getting Kubernetes version: %v", err)
+			}
 			n.ContainerRuntime = getContainerRuntime(&cc)
 			nodes = append(nodes, n)
 		}
@@ -1604,9 +1617,13 @@ func createNode(cc config.ClusterConfig, existing *config.ClusterConfig) (config
 		return cc, cp, nil
 	}
 
+	kubeVer, err := getKubernetesVersion(&cc)
+	if err != nil {
+		klog.Warningf("failed getting Kubernetes version: %v", err)
+	}
 	cp := config.Node{
 		Port:              cc.KubernetesConfig.NodePort,
-		KubernetesVersion: getKubernetesVersion(&cc),
+		KubernetesVersion: kubeVer,
 		ContainerRuntime:  getContainerRuntime(&cc),
 		ControlPlane:      true,
 		Worker:            true,
@@ -1653,12 +1670,32 @@ func autoSetDriverOptions(cmd *cobra.Command, drvName string) (err error) {
 
 // validateKubernetesVersion ensures that the requested version is reasonable
 func validateKubernetesVersion(old *config.ClusterConfig) {
-	nvs, _ := semver.Make(strings.TrimPrefix(getKubernetesVersion(old), version.VersionPrefix))
+	kubernetesVer, err := getKubernetesVersion(old)
+	if err != nil {
+		paramVersion := viper.GetString(kubernetesVersion)
+		paramVersion = strings.TrimPrefix(strings.ToLower(paramVersion), version.VersionPrefix)
+		if errors.Is(err, ErrKubernetesPatchNotFound) {
+			exit.Message(reason.PatchNotFound, "Unable to detect the latest patch release for specified major.minor version v{{.majorminor}}",
+				out.V{"majorminor": paramVersion})
+		}
+		exit.Message(reason.Usage, `Unable to parse "{{.kubernetes_version}}": {{.error}}`, out.V{"kubernetes_version": paramVersion, "error": err})
+
+	}
+
+	nvs, _ := semver.Make(strings.TrimPrefix(kubernetesVer, version.VersionPrefix))
 	oldestVersion := semver.MustParse(strings.TrimPrefix(constants.OldestKubernetesVersion, version.VersionPrefix))
 	defaultVersion := semver.MustParse(strings.TrimPrefix(constants.DefaultKubernetesVersion, version.VersionPrefix))
 	newestVersion := semver.MustParse(strings.TrimPrefix(constants.NewestKubernetesVersion, version.VersionPrefix))
 	zeroVersion := semver.MustParse(strings.TrimPrefix(constants.NoKubernetesVersion, version.VersionPrefix))
 
+	paramVersion := viper.GetString(kubernetesVersion)
+	paramVersion = strings.TrimPrefix(strings.ToLower(paramVersion), version.VersionPrefix)
+
+	if isTwoDigitSemver(paramVersion) {
+		if getLatestPatch(paramVersion) != "" {
+			out.Styled(style.Workaround, `Using Kubernetes {{.version}} since patch version was unspecified`, out.V{"version": nvs})
+		}
+	}
 	if nvs.Equals(zeroVersion) {
 		klog.Infof("No Kubernetes version set for minikube, setting Kubernetes version to %s", constants.NoKubernetesVersion)
 		return
@@ -1729,7 +1766,7 @@ func isBaseImageApplicable(drv string) bool {
 	return registry.IsKIC(drv)
 }
 
-func getKubernetesVersion(old *config.ClusterConfig) string {
+func getKubernetesVersion(old *config.ClusterConfig) (string, error) {
 	if viper.GetBool(noKubernetes) {
 		// Exit if --kubernetes-version is specified.
 		if viper.GetString(kubernetesVersion) != "" {
@@ -1758,12 +1795,21 @@ $ minikube config unset kubernetes-version`)
 		paramVersion = constants.NewestKubernetesVersion
 	}
 
-	nvs, err := semver.Make(strings.TrimPrefix(paramVersion, version.VersionPrefix))
+	kubernetesSemver := strings.TrimPrefix(strings.ToLower(paramVersion), version.VersionPrefix)
+	if isTwoDigitSemver(kubernetesSemver) {
+		potentialPatch := getLatestPatch(kubernetesSemver)
+		if potentialPatch != "" {
+			kubernetesSemver = potentialPatch
+		} else {
+			return "", ErrKubernetesPatchNotFound
+		}
+	}
+	nvs, err := semver.Make(kubernetesSemver)
 	if err != nil {
 		exit.Message(reason.Usage, `Unable to parse "{{.kubernetes_version}}": {{.error}}`, out.V{"kubernetes_version": paramVersion, "error": err})
 	}
 
-	return version.VersionPrefix + nvs.String()
+	return version.VersionPrefix + nvs.String(), nil
 }
 
 // validateDockerStorageDriver checks that docker is using overlay2
@@ -1848,7 +1894,11 @@ func validateBareMetal(drvName string) {
 	}
 
 	// conntrack is required starting with Kubernetes 1.18, include the release candidates for completion
-	version, _ := util.ParseKubernetesVersion(getKubernetesVersion(nil))
+	kubeVer, err := getKubernetesVersion(nil)
+	if err != nil {
+		klog.Warningf("failed getting Kubernetes version: %v", err)
+	}
+	version, _ := util.ParseKubernetesVersion(kubeVer)
 	if version.GTE(semver.MustParse("1.18.0-beta.1")) {
 		if _, err := exec.LookPath("conntrack"); err != nil {
 			exit.Message(reason.GuestMissingConntrack, "Sorry, Kubernetes {{.k8sVersion}} requires conntrack to be installed in root's path", out.V{"k8sVersion": version.String()})
@@ -1878,3 +1928,21 @@ func exitGuestProvision(err error) {
 	}
 	exit.Error(reason.GuestProvision, "error provisioning guest", err)
 }
+
+// Example input = 1.26 => output = "1.26.5"
+// Example input = 1.26.5 => output = "1.26.5"
+// Example input = 1.26.6 => output = ""
+func getLatestPatch(majorMinorVer string) string {
+	for _, k := range constants.ValidKubernetesVersions {
+		if strings.HasPrefix(k, fmt.Sprintf("v%s.", majorMinorVer)) {
+			return strings.TrimPrefix(k, version.VersionPrefix)
+		}
+
+	}
+	return ""
+}
+
+func isTwoDigitSemver(ver string) bool {
+	majorMinorOnly := regexp.MustCompile(`^(?P<major>0|[1-9]\d*)\.(?P<minor>0|[1-9]\d*)$`)
+	return majorMinorOnly.MatchString(ver)
+}

cmd/minikube/cmd/start_flags.go

@@ -811,7 +811,11 @@ func updateExistingConfigFromFlags(cmd *cobra.Command, existing *config.ClusterC
 	updateStringFromFlag(cmd, &cc.SocketVMnetPath, socketVMnetPath)
 
 	if cmd.Flags().Changed(kubernetesVersion) {
-		cc.KubernetesConfig.KubernetesVersion = getKubernetesVersion(existing)
+		kubeVer, err := getKubernetesVersion(existing)
+		if err != nil {
+			klog.Warningf("get kubernetesVersion failed : %v", err)
+		}
+		cc.KubernetesConfig.KubernetesVersion = kubeVer
 	}
 	if cmd.Flags().Changed(containerRuntime) {
 		cc.KubernetesConfig.ContainerRuntime = getContainerRuntime(existing)

cmd/minikube/cmd/start_test.go

@@ -25,6 +25,7 @@ import (
 	"github.com/spf13/cobra"
 	"github.com/spf13/viper"
 
+	"k8s.io/klog/v2"
 	cfg "k8s.io/minikube/pkg/minikube/config"
 	"k8s.io/minikube/pkg/minikube/constants"
 	"k8s.io/minikube/pkg/minikube/cruntime"
@@ -62,6 +63,16 @@ func TestGetKubernetesVersion(t *testing.T) {
 			paramVersion:    "v1.16.0",
 			cfg:             &cfg.ClusterConfig{KubernetesConfig: cfg.KubernetesConfig{KubernetesVersion: "v1.15.0"}},
 		},
+		{
+			description:     "kubernetes-version without patch version",
+			expectedVersion: "v1.16.15",
+			paramVersion:    "v1.16",
+		},
+		{
+			description:     "kubernetes-version without patch version",
+			expectedVersion: "v1.16.15",
+			paramVersion:    "1.16",
+		},
 		{
 			description:     "kubernetes-version given as 'stable', no config",
 			expectedVersion: constants.DefaultKubernetesVersion,
@@ -92,7 +103,10 @@ func TestGetKubernetesVersion(t *testing.T) {
 	for _, test := range tests {
 		t.Run(test.description, func(t *testing.T) {
 			viper.SetDefault(kubernetesVersion, test.paramVersion)
-			version := getKubernetesVersion(test.cfg)
+			version, err := getKubernetesVersion(test.cfg)
+			if err != nil {
+				klog.Warningf("get kubernetesVersion failed : %v", err)
+			}
 
 			// check whether we are getting the expected version
 			if version != test.expectedVersion {
@@ -451,6 +465,99 @@ func TestValidateRuntime(t *testing.T) {
 	}
 }
 
+func TestIsTwoDigitSemver(t *testing.T) {
+	var tcs = []struct {
+		desc     string
+		version  string
+		expected bool
+	}{
+		{
+			desc:     "a valid three digit version",
+			version:  "1.26.5",
+			expected: false,
+		},
+		{
+			desc:     "a valid two digit version",
+			version:  "1.26",
+			expected: true,
+		},
+		{
+			desc:     "a valid two digit version with a period",
+			version:  "1.26.",
+			expected: false,
+		},
+		{
+			desc:     "an invalid major version",
+			version:  "2",
+			expected: false,
+		},
+		{
+			desc:     "a valid major version",
+			version:  "1",
+			expected: false,
+		},
+		{
+			desc:     "a two digit version with a 0 as the major/minor components",
+			version:  "0.0",
+			expected: true,
+		},
+		{
+			desc:     "a two digit version with negative major version",
+			version:  "-1.0",
+			expected: false,
+		},
+		{
+			desc:     "a two digit vesion with negative minor version",
+			version:  "1.-1",
+			expected: false,
+		},
+		{
+			desc:     "a missing minor version",
+			version:  "1.",
+			expected: false,
+		},
+		{
+			desc:     "a missing major version",
+			version:  ".2",
+			expected: false,
+		},
+		{
+			desc:     "a valid two digit version with whitespace between components",
+			version:  "1. 1",
+			expected: false,
+		},
+		{
+			desc:     "a two digit version with a nondigit major component",
+			version:  "a.12",
+			expected: false,
+		},
+		{
+			desc:     "a two digit vesion with a nondigit minor component",
+			version:  "1.a",
+			expected: false,
+		},
+		{
+			desc:     "a two digit vesion with extraneous nondigits in minor component",
+			version:  "1.2a",
+			expected: false,
+		},
+		{
+			desc:     "a two digit vesion larger major/minor components",
+			version:  "123456789.987654321",
+			expected: true,
+		},
+	}
+	for _, tc := range tcs {
+		t.Run(tc.desc, func(t *testing.T) {
+			actual := isTwoDigitSemver(tc.version)
+			// check whether the function correctly verifies if it is a 2 digit semver
+			if actual != tc.expected {
+				t.Fatalf("test failed. Expected version v%s to return %v", tc.version, tc.expected)
+			}
+		})
+	}
+}
+
 func TestValidatePorts(t *testing.T) {
 	isMicrosoftWSL := detect.IsMicrosoftWSL()
 	type portTest struct {

pkg/minikube/out/out.go

@@ -21,12 +21,12 @@ import (
 	"bytes"
 	"fmt"
 	"html"
-	"html/template"
 	"io"
 	"os"
 	"path/filepath"
 	"strconv"
 	"strings"
+	"text/template"
 	"time"
 
 	"github.com/Delta456/box-cli-maker/v2"

pkg/minikube/reason/reason.go

@@ -57,6 +57,11 @@ func (k *Kind) IssueURLs() []string {
 
 // Sections are ordered roughly by stack dependencies
 var (
+	// minikube could not find a patch for the provided major.minor version
+	PatchNotFound = Kind{ID: "MK_PATCH_NOT_FOUND", ExitCode: ExProgramUsage,
+		Advice: translate.T("Specify --kubernetes-version in v<major>.<minor.<build> form. example: 'v1.1.14'"),
+	}
+
 	// minikube has been passed an incorrect parameter
 	Usage = Kind{ID: "MK_USAGE", ExitCode: ExProgramUsage}
 	// minikube has no current cluster running