fix: preserve vendor suffixes in KubeVersion.GitVersion

Helm 3.19.0 introduced a regression where vendor-specific suffixes
(e.g., -gke.1245000, -eks-4096722, +) are stripped from
.Capabilities.KubeVersion.GitVersion, breaking charts that detect
managed Kubernetes platforms.

The root cause was using k8sversion.ParseGeneric().String() which
intentionally discards vendor suffixes. The fix stores both the full
version (with vendor suffix) and a normalized version. String() returns
the normalized version for constraint checking (e.g., ">= 1.21.0"),
while Version/GitVersion preserve the full string for template access.

Fixes #31423
Related to #31063, #31078

Signed-off-by: Benoit Tigeot <benoit.tigeot@lifen.fr>

pkg/action/action.go

@@ -230,7 +230,7 @@ func (cfg *Configuration) renderResources(ch *chart.Chart, values common.Values,
 
 	if ch.Metadata.KubeVersion != "" {
 		if !chartutil.IsCompatibleRange(ch.Metadata.KubeVersion, caps.KubeVersion.String()) {
-			return hs, b, "", fmt.Errorf("chart requires kubeVersion: %s which is incompatible with Kubernetes %s", ch.Metadata.KubeVersion, caps.KubeVersion.String())
+			return hs, b, "", fmt.Errorf("chart requires kubeVersion: %s which is incompatible with Kubernetes %s", ch.Metadata.KubeVersion, caps.KubeVersion.Version)
 		}
 	}
 

pkg/action/install_test.go

@@ -572,7 +572,7 @@ func TestInstallRelease_KubeVersion(t *testing.T) {
 	vals = map[string]interface{}{}
 	_, err = instAction.Run(buildChart(withKube(">=99.0.0")), vals)
 	is.Error(err)
-	is.Contains(err.Error(), "chart requires kubeVersion")
+	is.Contains(err.Error(), "chart requires kubeVersion: >=99.0.0 which is incompatible with Kubernetes v1.20.")
 }
 
 func TestInstallRelease_Wait(t *testing.T) {

pkg/chart/common/capabilities.go

@@ -19,6 +19,7 @@ import (
 	"fmt"
 	"slices"
 	"strconv"
+	"strings"
 
 	"k8s.io/client-go/kubernetes/scheme"
 
@@ -39,9 +40,11 @@ var (
 	DefaultVersionSet = allKnownVersions()
 
 	// DefaultCapabilities is the default set of capabilities.
+	version             = fmt.Sprintf("v%s.%s.0", k8sVersionMajor, k8sVersionMinor)
 	DefaultCapabilities = &Capabilities{
 		KubeVersion: KubeVersion{
-			Version: fmt.Sprintf("v%s.%s.0", k8sVersionMajor, k8sVersionMinor),
+			Version:           version,
+			normalizedVersion: version,
 			Major:             k8sVersionMajor,
 			Minor:             k8sVersionMinor,
 		},
@@ -70,15 +73,22 @@ func (capabilities *Capabilities) Copy() *Capabilities {
 
 // KubeVersion is the Kubernetes version.
 type KubeVersion struct {
-	Version string // Kubernetes version
+	Version           string // Full version (e.g., v1.33.4-gke.1245000)
+	normalizedVersion string // Normalized for constraint checking (e.g., v1.33.4)
 	Major             string // Kubernetes major version
 	Minor             string // Kubernetes minor version
 }
 
-// String implements fmt.Stringer
-func (kv *KubeVersion) String() string { return kv.Version }
+// String implements fmt.Stringer.
+// Returns the normalized version used for constraint checking.
+func (kv *KubeVersion) String() string {
+	if kv.normalizedVersion != "" {
+		return kv.normalizedVersion
+	}
+	return kv.Version
+}
 
-// GitVersion returns the Kubernetes version string.
+// GitVersion returns the full Kubernetes version string.
 //
 // Deprecated: use KubeVersion.Version.
 func (kv *KubeVersion) GitVersion() string { return kv.Version }
@@ -91,8 +101,19 @@ func ParseKubeVersion(version string) (*KubeVersion, error) {
 	if err != nil {
 		return nil, err
 	}
+
+	// Preserve original input (e.g., v1.33.4-gke.1245000)
+	gitVersion := version
+	if !strings.HasPrefix(version, "v") {
+		gitVersion = "v" + version
+	}
+
+	// Normalize for constraint checking (strips all suffixes)
+	normalizedVer := "v" + sv.String()
+
 	return &KubeVersion{
-		Version: "v" + sv.String(),
+		Version:           gitVersion,
+		normalizedVersion: normalizedVer,
 		Major:             strconv.FormatUint(uint64(sv.Major()), 10),
 		Minor:             strconv.FormatUint(uint64(sv.Minor()), 10),
 	}, nil

pkg/chart/common/capabilities_test.go

@@ -83,18 +83,41 @@ func TestParseKubeVersion(t *testing.T) {
 	}
 }
 
-func TestParseKubeVersionSuffix(t *testing.T) {
-	kv, err := ParseKubeVersion("v1.28+")
+func TestParseKubeVersionWithVendorSuffixes(t *testing.T) {
+	tests := []struct {
+		name       string
+		input      string
+		wantVer    string
+		wantString string
+		wantMajor  string
+		wantMinor  string
+	}{
+		{"GKE vendor suffix", "v1.33.4-gke.1245000", "v1.33.4-gke.1245000", "v1.33.4", "1", "33"},
+		{"GKE without v", "1.30.2-gke.1587003", "v1.30.2-gke.1587003", "v1.30.2", "1", "30"},
+		{"EKS trailing +", "v1.28+", "v1.28+", "v1.28", "1", "28"},
+		{"EKS + without v", "1.28+", "v1.28+", "v1.28", "1", "28"},
+		{"Standard version", "v1.31.0", "v1.31.0", "v1.31.0", "1", "31"},
+		{"Standard without v", "1.29.0", "v1.29.0", "v1.29.0", "1", "29"},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			kv, err := ParseKubeVersion(tt.input)
 			if err != nil {
-		t.Errorf("Expected v1.28+ to parse successfully")
+				t.Fatalf("ParseKubeVersion() error = %v", err)
 			}
-	if kv.Version != "v1.28" {
-		t.Errorf("Expected parsed KubeVersion.Version to be v1.28, got %q", kv.String())
+			if kv.Version != tt.wantVer {
+				t.Errorf("Version = %q, want %q", kv.Version, tt.wantVer)
 			}
-	if kv.Major != "1" {
-		t.Errorf("Expected parsed KubeVersion.Major to be 1, got %q", kv.Major)
+			if kv.String() != tt.wantString {
+				t.Errorf("String() = %q, want %q", kv.String(), tt.wantString)
+			}
+			if kv.Major != tt.wantMajor {
+				t.Errorf("Major = %q, want %q", kv.Major, tt.wantMajor)
+			}
+			if kv.Minor != tt.wantMinor {
+				t.Errorf("Minor = %q, want %q", kv.Minor, tt.wantMinor)
 			}
-	if kv.Minor != "28" {
-		t.Errorf("Expected parsed KubeVersion.Minor to be 28, got %q", kv.Minor)
+		})
 	}
 }