cli: add --kubernetes flag (#1226)

The flag can be used to specify a Kubernetes version
in format MAJOR.MINOR and let the CLI extend the
value with the patch version.

cli/internal/cmd/configgenerate.go

@@ -8,14 +8,18 @@ package cmd
 
 import (
 	"fmt"
+	"strings"
 
 	"github.com/edgelesssys/constellation/v2/internal/cloud/cloudprovider"
+	"github.com/edgelesssys/constellation/v2/internal/compatibility"
 	"github.com/edgelesssys/constellation/v2/internal/config"
 	"github.com/edgelesssys/constellation/v2/internal/constants"
 	"github.com/edgelesssys/constellation/v2/internal/file"
+	"github.com/edgelesssys/constellation/v2/internal/versions"
 	"github.com/siderolabs/talos/pkg/machinery/config/encoder"
 	"github.com/spf13/afero"
 	"github.com/spf13/cobra"
+	"golang.org/x/mod/semver"
 )
 
 func newConfigGenerateCmd() *cobra.Command {
@@ -31,12 +35,14 @@ func newConfigGenerateCmd() *cobra.Command {
 		RunE:              runConfigGenerate,
 	}
 	cmd.Flags().StringP("file", "f", constants.ConfigFilename, "path to output file, or '-' for stdout")
+	cmd.Flags().StringP("kubernetes", "k", semver.MajorMinor(config.Default().KubernetesVersion), "Kubernetes version to use in format MAJOR.MINOR")
 
 	return cmd
 }
 
 type generateFlags struct {
-	file string
+	file       string
+	k8sVersion string
 }
 
 type configGenerateCmd struct {
@@ -64,6 +70,11 @@ func (cg *configGenerateCmd) configGenerate(cmd *cobra.Command, fileHandler file
 	cg.log.Debugf("Parsed flags as %v", flags)
 	cg.log.Debugf("Using cloud provider %s", provider.String())
 	conf := createConfig(provider)
+	extendedVersion := config.K8sVersionFromMajorMinor(flags.k8sVersion)
+	if extendedVersion == "" {
+		return fmt.Errorf("kubernetes (%s) does not specify a valid Kubernetes version. Supported versions: %s", strings.TrimPrefix(flags.k8sVersion, "v"), supportedVersions())
+	}
+	conf.KubernetesVersion = extendedVersion
 	if flags.file == "-" {
 		content, err := encoder.NewEncoder(conf).Encode()
 		if err != nil {
@@ -101,13 +112,36 @@ func createConfig(provider cloudprovider.Provider) *config.Config {
 	return conf
 }
 
+// supportedVersions prints the supported version without v prefix and without patch version.
+// Should only be used when accepting Kubernetes versions from --kubernetes.
+func supportedVersions() string {
+	builder := strings.Builder{}
+	for i, version := range versions.SupportedK8sVersions() {
+		if i > 0 {
+			builder.WriteString(" ")
+		}
+		builder.WriteString(strings.TrimPrefix(semver.MajorMinor(version), "v"))
+	}
+	return builder.String()
+}
+
 func parseGenerateFlags(cmd *cobra.Command) (generateFlags, error) {
 	file, err := cmd.Flags().GetString("file")
 	if err != nil {
-		return generateFlags{}, fmt.Errorf("parsing config generate flags: %w", err)
+		return generateFlags{}, fmt.Errorf("parsing file flag: %w", err)
 	}
+	k8sVersion, err := cmd.Flags().GetString("kubernetes")
+	if err != nil {
+		return generateFlags{}, fmt.Errorf("parsing kuberentes flag: %w", err)
+	}
+	prefixedVersion := compatibility.EnsurePrefixV(k8sVersion)
+	if !semver.IsValid(prefixedVersion) {
+		return generateFlags{}, fmt.Errorf("kubernetes flag does not specify a valid semantic version: %s", k8sVersion)
+	}
+
 	return generateFlags{
-		file: file,
+		file:       file,
+		k8sVersion: prefixedVersion,
 	}, nil
 }
 

cli/internal/cmd/configgenerate_test.go

@@ -15,12 +15,54 @@ import (
 	"github.com/edgelesssys/constellation/v2/internal/constants"
 	"github.com/edgelesssys/constellation/v2/internal/file"
 	"github.com/edgelesssys/constellation/v2/internal/logger"
+	"github.com/edgelesssys/constellation/v2/internal/versions"
 	"github.com/spf13/afero"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+	"golang.org/x/mod/semver"
 	"gopkg.in/yaml.v3"
 )
 
+func TestConfigGenerateKubernetesVersion(t *testing.T) {
+	testCases := map[string]struct {
+		version string
+		wantErr bool
+	}{
+		"success": {
+			version: semver.MajorMinor(string(versions.Default)),
+		},
+		"no semver": {
+			version: "asdf",
+			wantErr: true,
+		},
+		"not supported": {
+			version: "1111",
+			wantErr: true,
+		},
+	}
+
+	for name, tc := range testCases {
+		t.Run(name, func(t *testing.T) {
+			assert := assert.New(t)
+			require := require.New(t)
+
+			fileHandler := file.NewHandler(afero.NewMemMapFs())
+			cmd := newConfigGenerateCmd()
+			err := cmd.Flags().Set("kubernetes", tc.version)
+			require.NoError(err)
+
+			cg := &configGenerateCmd{log: logger.NewTest(t)}
+			err = cg.configGenerate(cmd, fileHandler, cloudprovider.Unknown)
+
+			if tc.wantErr {
+				assert.Error(err)
+				return
+			}
+			assert.NoError(err)
+		})
+	}
+}
+
 func TestConfigGenerateDefault(t *testing.T) {
 	assert := assert.New(t)
 	require := require.New(t)

internal/config/validation.go

@@ -327,19 +327,35 @@ func (c *Config) validateK8sVersion(fl validator.FieldLevel) bool {
 	if !semver.IsValid(configVersion) {
 		return false
 	}
-	var extendedVersion string
+
-	switch semver.MajorMinor(configVersion) {
+	extendedVersion := K8sVersionFromMajorMinor(semver.MajorMinor(configVersion))
-	case semver.MajorMinor(string(versions.V1_24)):
+	if extendedVersion == "" {
-		extendedVersion = string(versions.V1_24)
-	case semver.MajorMinor(string(versions.V1_25)):
-		extendedVersion = string(versions.V1_25)
-	case semver.MajorMinor(string(versions.V1_26)):
-		extendedVersion = string(versions.V1_26)
-	default:
 		return false
 	}
+
+	valid := versions.IsSupportedK8sVersion(extendedVersion)
+	if !valid {
+		return false
+	}
+
 	c.KubernetesVersion = extendedVersion
-	return versions.IsSupportedK8sVersion(extendedVersion)
+	return true
+}
+
+// K8sVersionFromMajorMinor takes a semver in format MAJOR.MINOR
+// and returns the version in format MAJOR.MINOR.PATCH with the
+// supported patch version as PATCH.
+func K8sVersionFromMajorMinor(version string) string {
+	switch version {
+	case semver.MajorMinor(string(versions.V1_24)):
+		return string(versions.V1_24)
+	case semver.MajorMinor(string(versions.V1_25)):
+		return string(versions.V1_25)
+	case semver.MajorMinor(string(versions.V1_26)):
+		return string(versions.V1_26)
+	default:
+		return ""
+	}
 }
 
 func registerVersionCompatibilityError(ut ut.Translator) error {