fix(tools): Ensure GetCoreDNSVersion handles canonical semver

this allows us to parse and ignore patch version, etc. in params.

Author: thunderboltsid

api/versions/coredns.go

@@ -25,21 +25,22 @@ import (
 var (
 	// Command-line flags
 	outputFile           = flag.String("output", "api/versions/coredns.go", "Output file path")
-	minKubernetesVersion = flag.String("min-kubernetes-version", "v1.22", "Minimum Kubernetes version to include (semver format)")
+	minKubernetesVersion = flag.String("min-kubernetes-version", "v1.22.0", "Minimum Kubernetes version to include (semver format)")
 )
 
 const (
 	constantsURLTemplate = "https://raw.githubusercontent.com/kubernetes/kubernetes/%s/cmd/kubeadm/app/constants/constants.go"
 	branchesAPIURL       = "https://api.github.com/repos/kubernetes/kubernetes/branches?per_page=100&page=%d"
 )
 
-var goTemplate = `
-// Copyright 2024 Nutanix. All rights reserved.
-// SPDX-License-Identifier: Apache-2.0
-// Code generated by script; DO NOT EDIT. Run 'make coredns.sync' instead
+var goTemplate = `// Code generated by script; DO NOT EDIT. Run 'make coredns.sync' instead
 
 package versions
 
+import (
+	"golang.org/x/mod/semver"
+)
+
 // Kubernetes versions
 const (
 {{- range .KubernetesConstants }}
@@ -55,26 +56,40 @@ const (
 )
 
 // kubernetesToCoreDNSVersion maps Kubernetes versions to CoreDNS versions.
+// This map is unexported to prevent external modification.
 var kubernetesToCoreDNSVersion = map[string]string{
 {{- range .VersionMap }}
 	{{ .KubernetesConst }}: {{ .CoreDNSConst }},
 {{- end }}
 }
 
 // GetCoreDNSVersion returns the CoreDNS version for a given Kubernetes version.
+// It accepts versions with or without the "v" prefix and handles full semver versions.
+// The function maps based on the major and minor versions (e.g., "v1.27").
 // If the Kubernetes version is not found, it returns an empty string and false.
 func GetCoreDNSVersion(kubernetesVersion string) (string, bool) {
-	version, found := kubernetesToCoreDNSVersion[kubernetesVersion]
+	// Normalize the version using semver
+	normalizedVersion := semver.Canonical(kubernetesVersion)
+	if normalizedVersion == "" {
+		// Handle invalid version strings
+		return "", false
+	}
+
+	// Extract major and minor versions
+	majorMinor := semver.MajorMinor(normalizedVersion) // e.g., "v1.27"
+
+	// Lookup the CoreDNS version using the major and minor version
+	version, found := kubernetesToCoreDNSVersion[majorMinor]
 	return version, found
 }
 
 // GetKubernetesToCoreDNSVersionMap returns a copy of the Kubernetes to CoreDNS version mapping.
+// The map keys are Kubernetes versions in "vMAJOR.MINOR" format.
 func GetKubernetesToCoreDNSVersionMap() map[string]string {
 	copyMap := make(map[string]string, len(kubernetesToCoreDNSVersion))
 	for k, v := range kubernetesToCoreDNSVersion {
 		copyMap[k] = v
 	}
-
 	return copyMap
 }
 `
@@ -86,6 +101,10 @@ func main() {
 	if !strings.HasPrefix(*minKubernetesVersion, "v") {
 		*minKubernetesVersion = "v" + *minKubernetesVersion
 	}
+	// Ensure minKubernetesVersion has patch version
+	if semver.Prerelease(*minKubernetesVersion) == "" && semver.Build(*minKubernetesVersion) == "" && len(strings.Split(semver.Canonical(*minKubernetesVersion), ".")) == 2 {
+		*minKubernetesVersion += ".0"
+	}
 
 	versions, err := fetchKubernetesVersions(*minKubernetesVersion)
 	if err != nil {
@@ -117,20 +136,24 @@ func fetchKubernetesVersions(minVersion string) ([]string, error) {
 		if err != nil {
 			return nil, err
 		}
+
 		if len(branchNames) == 0 {
 			break
 		}
+
 		for _, branch := range branchNames {
 			if strings.HasPrefix(branch, "release-1.") {
 				version := strings.TrimPrefix(branch, "release-")
-				semverVersion := "v" + version
+				semverVersion := "v" + version + ".0"
 				if semver.Compare(semverVersion, minVersion) >= 0 {
 					versions = append(versions, version)
 				}
 			}
 		}
+
 		page++
 	}
+
 	if len(versions) == 0 {
 		return nil, errors.New("no Kubernetes versions found")
 	}
@@ -139,13 +162,16 @@ func fetchKubernetesVersions(minVersion string) ([]string, error) {
 	for _, v := range versions {
 		versionSet[v] = struct{}{}
 	}
+
 	versions = nil
 	for v := range versionSet {
 		versions = append(versions, v)
 	}
+
 	sort.Slice(versions, func(i, j int) bool {
-		return semver.Compare("v"+versions[i], "v"+versions[j]) < 0
+		return semver.Compare("v"+versions[i]+".0", "v"+versions[j]+".0") < 0
 	})
+
 	return versions, nil
 }
 
@@ -155,6 +181,7 @@ func fetchBranchNames(url string) ([]string, error) {
 	if err != nil {
 		return nil, fmt.Errorf("HTTP GET error: %w", err)
 	}
+
 	defer resp.Body.Close()
 
 	if resp.StatusCode != http.StatusOK {
@@ -164,6 +191,7 @@ func fetchBranchNames(url string) ([]string, error) {
 	var branches []struct {
 		Name string `json:"name"`
 	}
+
 	if err := json.NewDecoder(resp.Body).Decode(&branches); err != nil {
 		return nil, fmt.Errorf("decoding JSON error: %w", err)
 	}
@@ -172,13 +200,13 @@ func fetchBranchNames(url string) ([]string, error) {
 	for _, branch := range branches {
 		branchNames = append(branchNames, branch.Name)
 	}
+
 	return branchNames, nil
 }
 
 func fetchCoreDNSVersions(versions []string) (map[string]string, error) {
 	versionMap := make(map[string]string)
 	re := regexp.MustCompile(`CoreDNSVersion\s*=\s*"([^"]+)"`)
-
 	for _, k8sVersion := range versions {
 		branch := "release-" + k8sVersion
 		url := fmt.Sprintf(constantsURLTemplate, branch)
@@ -187,7 +215,17 @@ func fetchCoreDNSVersions(versions []string) (map[string]string, error) {
 			fmt.Fprintf(os.Stderr, "Warning: Failed for Kubernetes %s: %v\n", k8sVersion, err)
 			continue
 		}
-		versionMap[k8sVersion] = coreDNSVersion
+
+		// Normalize CoreDNS version using semver
+		coreDNSVersion = semver.Canonical(coreDNSVersion)
+		if coreDNSVersion == "" {
+			fmt.Fprintf(os.Stderr, "Warning: Invalid CoreDNS version '%s' for Kubernetes %s\n", coreDNSVersion, k8sVersion)
+			continue
+		}
+		// Prefix Kubernetes version with "v" and add ".0" for patch version
+		fullVersion := "v" + k8sVersion + ".0"
+		majorMinor := semver.MajorMinor(fullVersion)
+		versionMap[majorMinor] = coreDNSVersion
 	}
 
 	if len(versionMap) == 0 {
@@ -202,6 +240,7 @@ func extractCoreDNSVersion(url string, re *regexp.Regexp) (string, error) {
 	if err != nil {
 		return "", fmt.Errorf("HTTP GET error: %w", err)
 	}
+
 	defer resp.Body.Close()
 
 	if resp.StatusCode != http.StatusOK {
@@ -218,7 +257,13 @@ func extractCoreDNSVersion(url string, re *regexp.Regexp) (string, error) {
 		return "", errors.New("CoreDNSVersion not found")
 	}
 
-	return matches[1], nil
+	// Ensure CoreDNS version includes "v" prefix
+	coreDNSVersion := matches[1]
+	if !strings.HasPrefix(coreDNSVersion, "v") {
+		coreDNSVersion = "v" + coreDNSVersion
+	}
+
+	return coreDNSVersion, nil
 }
 
 func generateGoFile(versionMap map[string]string, outputPath string) error {
@@ -255,13 +300,13 @@ func prepareTemplateData(versionMap map[string]string) map[string]interface{} {
 		Name    string
 		Version string
 	}
-	var k8sConstants []Const
-	var coreDNSConstants []Const
+
 	type versionMapEntry struct {
 		KubernetesVersion string
 		KubernetesConst   string
 		CoreDNSConst      string
 	}
+
 	var versionMapList []versionMapEntry
 
 	// Maps for deduplication
@@ -274,46 +319,48 @@ func prepareTemplateData(versionMap map[string]string) map[string]interface{} {
 		uniqueCoreDNSVersions[coreDNSVersion] = struct{}{}
 	}
 
-	// Generate constants for Kubernetes versions
-	for k8sVersion := range versionMap {
-		constName := versionToConst("Kubernetes", k8sVersion)
-		k8sConstMap[k8sVersion] = constName
-	}
-
+	var k8sConstants []Const
+	var coreDNSConstants []Const
 	// Generate constants for CoreDNS versions
 	for coreDNSVersion := range uniqueCoreDNSVersions {
 		constName := versionToConst("CoreDNS", coreDNSVersion)
 		coreDNSConstMap[coreDNSVersion] = constName
+		coreDNSConstants = append(coreDNSConstants, Const{Name: constName, Version: coreDNSVersion})
 	}
 
-	// Prepare constants slices
-	for k8sVersion, constName := range k8sConstMap {
-		k8sConstants = append(k8sConstants, Const{Name: constName, Version: k8sVersion})
+	// Generate constants and mapping for Kubernetes versions
+	for k8sVersion := range versionMap {
+		// Constants and mapping use major.minor versions
+		majorMinor := semver.MajorMinor(k8sVersion)
+		if _, exists := k8sConstMap[majorMinor]; !exists {
+			constName := versionToConst("Kubernetes", majorMinor)
+			k8sConstMap[majorMinor] = constName
+			k8sConstants = append(k8sConstants, Const{Name: constName, Version: majorMinor})
+		}
 	}
-	for coreDNSVersion, constName := range coreDNSConstMap {
-		coreDNSConstants = append(coreDNSConstants, Const{Name: constName, Version: coreDNSVersion})
+
+	// Map Kubernetes constants to CoreDNS constants
+	for k8sVersion, coreDNSVersion := range versionMap {
+		majorMinor := semver.MajorMinor(k8sVersion)
+		versionMapList = append(versionMapList, versionMapEntry{
+			KubernetesVersion: majorMinor,
+			KubernetesConst:   k8sConstMap[majorMinor],
+			CoreDNSConst:      coreDNSConstMap[coreDNSVersion],
+		})
 	}
 
 	// Sort constants
 	sort.Slice(k8sConstants, func(i, j int) bool {
-		return semver.Compare("v"+k8sConstants[i].Version, "v"+k8sConstants[j].Version) < 0
+		return semver.Compare(k8sConstants[i].Version, k8sConstants[j].Version) < 0
 	})
+
 	sort.Slice(coreDNSConstants, func(i, j int) bool {
 		return semver.Compare(coreDNSConstants[i].Version, coreDNSConstants[j].Version) < 0
 	})
 
-	// Map Kubernetes constants to CoreDNS constants
-	for k8sVersion, coreDNSVersion := range versionMap {
-		versionMapList = append(versionMapList, versionMapEntry{
-			KubernetesVersion: k8sVersion,
-			KubernetesConst:   k8sConstMap[k8sVersion],
-			CoreDNSConst:      coreDNSConstMap[coreDNSVersion],
-		})
-	}
-
 	// Sort version map
 	sort.Slice(versionMapList, func(i, j int) bool {
-		return semver.Compare("v"+versionMapList[i].KubernetesVersion, "v"+versionMapList[j].KubernetesVersion) < 0
+		return semver.Compare(versionMapList[i].KubernetesVersion, versionMapList[j].KubernetesVersion) < 0
 	})
 
 	data := map[string]interface{}{
@@ -327,9 +374,9 @@ func prepareTemplateData(versionMap map[string]string) map[string]interface{} {
 
 func versionToConst(prefix, version string) string {
 	// Remove 'v' prefix if present
-	version = strings.TrimPrefix(version, "v")
+	versionNoV := strings.TrimPrefix(version, "v")
 	// Replace dots with underscores
-	version = strings.ReplaceAll(version, ".", "_")
+	versionNoV = strings.ReplaceAll(versionNoV, ".", "_")
 	// Prepend the prefix and 'V'
-	return prefix + "_V" + version
+	return prefix + "_V" + versionNoV
 }