feat: add check metadata command to clusterctl

This adds a new command to clusterctl which given a version number will
check that there is a release series defined in a metadata file for
that version.

The main use case for this is a CI check. When building a release of a
provider that is for a new major or minor version its required that a
new release series is added to the providers metadata file. This ensures
that the correct version of the provider is installed when initializing
a management cluster.

A command failure for release pipelines is that the metadata file hasn't
been updated.

Signed-off-by: Richard Case <[email protected]>

Author: richardcase

cmd/clusterctl/cmd/validate_metadata.go

@@ -0,0 +1,108 @@
+/*
+Copyright 2025 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package cmd
+
+import (
+	"fmt"
+	"os"
+	"strings"
+
+	"github.com/blang/semver/v4"
+	"github.com/spf13/cobra"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/runtime/serializer"
+	"sigs.k8s.io/cluster-api/cmd/clusterctl/cmd/internal/templates"
+
+	clusterctlv1 "sigs.k8s.io/cluster-api/cmd/clusterctl/api/v1alpha3"
+)
+
+type checkMetadataOptions struct {
+	file    string
+	version string
+}
+
+var (
+	checkMetadataOpts = &checkMetadataOptions{}
+
+	checkMetadataLong = templates.LongDesc(`
+		Command that will check that the given metadata file contains an entry
+		for the supplied version number.
+
+		This is intended to be used in CI to fail a release build early if
+		there is no metadata entry for the release version series.
+	`)
+
+	checkMetadataExample = templates.Examples(`
+		clusterctl check-metadata -f metadata.yaml --version v1.0.17
+	`)
+
+	checkMetadataCmd = &cobra.Command{
+		Use:     "check-metadata",
+		GroupID: groupOther,
+		Short:   "Validate the metadata file given a version number",
+		Long:    templates.LongDesc(checkMetadataLong),
+		Example: checkMetadataExample,
+		Args:    cobra.NoArgs,
+		RunE: func(cmd *cobra.Command, args []string) error {
+			return runCheckMetadata()
+		},
+	}
+)
+
+func init() {
+	checkMetadataCmd.Flags().StringVarP(&checkMetadataOpts.file, "file", "f", "", "Path to metadata.yaml file to check")
+	checkMetadataCmd.Flags().StringVar(&checkMetadataOpts.version, "version", "", "The version number to check against the metadata file")
+
+	checkMetadataCmd.MarkFlagRequired("file")
+	checkMetadataCmd.MarkFlagRequired("version")
+
+	RootCmd.AddCommand(checkMetadataCmd)
+}
+
+func runCheckMetadata() error {
+	versionToCheck := strings.TrimPrefix(checkMetadataOpts.version, "v")
+
+	ver, err := semver.Parse(versionToCheck)
+	if err != nil {
+		return fmt.Errorf("failed parsing %s as semver version: %w", checkMetadataOpts.version, err)
+	}
+
+	fileData, err := os.ReadFile(checkMetadataOpts.file)
+	if err != nil {
+		return fmt.Errorf("failed reading file %s: %w", checkMetadataOpts.file, err)
+	}
+
+	scheme := runtime.NewScheme()
+	if err := clusterctlv1.AddToScheme(scheme); err != nil {
+		return fmt.Errorf("failed to add metadata type to scheme: %w", err)
+	}
+	metadata := &clusterctlv1.Metadata{}
+	codecFactory := serializer.NewCodecFactory(scheme)
+
+	if err := runtime.DecodeInto(codecFactory.UniversalDecoder(), fileData, metadata); err != nil {
+		return fmt.Errorf("failed decoding metadata from file: %w", err)
+	}
+
+	for _, series := range metadata.ReleaseSeries {
+		if series.Major == int32(ver.Major) && series.Minor == int32(ver.Minor) {
+			fmt.Printf("Success, there is a release series defined in the metadata file\n")
+			return nil
+		}
+	}
+
+	return fmt.Errorf("failed to find release series %s in metadata files %s", "", checkMetadataOpts.file)
+}