Allow using kubectl built-in kustomize if separate kustomize binary is missing

chartify_test.go

@@ -166,3 +166,34 @@
 		})
 	}
 }
+
+func TestKubectlKustomizeFallback(t *testing.T) {
+	// Test the fallback functionality when kustomize binary is not available
+	// Use a non-existent binary name to simulate missing kustomize
+	r := New(UseHelm3(true), KustomizeBin("non-existent-kustomize-binary"))
+
+	// Test that isKustomizeBinaryAvailable returns false for non-existent binary
+	available := r.isKustomizeBinaryAvailable()
+	require.False(t, available, "non-existent binary should not be available")
+
+	// Test the kustomizeBuildCommand function returns kubectl command for fallback
+	buildArgs := []string{"-o", "/tmp/output.yaml", "build", "--enable-helm"}
+	targetDir := "/tmp/testdir"
+
+	cmd, args, err := r.kustomizeBuildCommand(buildArgs, targetDir)
+	require.NoError(t, err)
+	require.Equal(t, "kubectl", cmd)
+	require.Contains(t, args, "kustomize")
+	require.Contains(t, args, targetDir)
+	require.Contains(t, args, "--enable-helm")
+
+	// Test with a real kustomize binary (should not fallback)
+	r2 := New(UseHelm3(true), KustomizeBin("kustomize"))
+	available2 := r2.isKustomizeBinaryAvailable()
+	require.True(t, available2, "kustomize binary should be available")
+
+	cmd2, args2, err2 := r2.kustomizeBuildCommand(buildArgs, targetDir)
+	require.NoError(t, err2)
+	require.Equal(t, "kustomize", cmd2)
+	require.Equal(t, append(buildArgs, targetDir), args2)
+}

go.sum

@@ -343,8 +343,6 @@ gopkg.in/yaml.v2 v2.4.0/go.mod h1:RDklbk79AGWmwhnvt/jBztapEOGDOx6ZbXqjP6csGnQ=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
-helm.sh/helm/v3 v3.18.5 h1:Cc3Z5vd6kDrZq9wO9KxKLNEickiTho6/H/dBNRVSos4=
-helm.sh/helm/v3 v3.18.5/go.mod h1:L/dXDR2r539oPlFP1PJqKAC1CUgqHJDLkxKpDGrWnyg=
 helm.sh/helm/v3 v3.18.6 h1:S/2CqcYnNfLckkHLI0VgQbxgcDaU3N4A/46E3n9wSNY=
 helm.sh/helm/v3 v3.18.6/go.mod h1:L/dXDR2r539oPlFP1PJqKAC1CUgqHJDLkxKpDGrWnyg=
 k8s.io/api v0.33.3 h1:SRd5t//hhkI1buzxb288fy2xvjubstenEKL9K51KBI8=

kubectl_fallback_integration_test.go

@@ -0,0 +1,116 @@
+package chartify
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestKubectlKustomizeFallbackIntegration(t *testing.T) {
+	// Create a temporary directory for our test
+	tempDir, err := os.MkdirTemp("", "kubectl-fallback-integration")
+	require.NoError(t, err)
+	defer os.RemoveAll(tempDir)
+
+	// Create a simple kubernetes manifest
+	manifestContent := `apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: test-app
+  namespace: default
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: test-app
+  template:
+    metadata:
+      labels:
+        app: test-app
+    spec:
+      containers:
+      - name: app
+        image: nginx:1.20
+        ports:
+        - containerPort: 80
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: test-app-service
+  namespace: default
+spec:
+  selector:
+    app: test-app
+  ports:
+  - protocol: TCP
+    port: 80
+    targetPort: 80
+  type: ClusterIP
+`
+
+	manifestPath := filepath.Join(tempDir, "manifest.yaml")
+	err = os.WriteFile(manifestPath, []byte(manifestContent), 0644)
+	require.NoError(t, err)
+
+	// Test with non-existent kustomize binary (should use kubectl fallback)
+	t.Run("kubectl fallback scenario", func(t *testing.T) {
+		runner := New(KustomizeBin("non-existent-kustomize"))
+
+		// Test kustomize build with image replacement
+		kustomizeOpts := KustomizeOpts{
+			Images: []KustomizeImage{
+				{Name: "nginx", NewTag: "1.21"},
+			},
+			NamePrefix: "prefix-",
+			Namespace:  "test-namespace",
+		}
+
+		// Generate kustomization content
+		relPath := "."
+		kustomizationContent, err := runner.generateKustomizationFile(relPath, kustomizeOpts)
+		require.NoError(t, err)
+
+		// Verify the generated kustomization content
+		kustomizationStr := string(kustomizationContent)
+		require.Contains(t, kustomizationStr, "resources:")
+		require.NotContains(t, kustomizationStr, "bases:") // Should not use deprecated bases
+		require.Contains(t, kustomizationStr, "images:")
+		require.Contains(t, kustomizationStr, "namePrefix: prefix-")
+		require.Contains(t, kustomizationStr, "namespace: test-namespace")
+		require.Contains(t, kustomizationStr, "nginx")
+		require.Contains(t, kustomizationStr, "1.21")
+
+		// Write kustomization.yaml
+		kustomizationPath := filepath.Join(tempDir, "kustomization.yaml")
+		err = os.WriteFile(kustomizationPath, kustomizationContent, 0644)
+		require.NoError(t, err)
+
+		// Test the build command generation for kubectl fallback
+		buildArgs := []string{"-o", "/tmp/output.yaml", "build", "--enable-helm"}
+		cmd, args, err := runner.kustomizeBuildCommand(buildArgs, tempDir)
+		require.NoError(t, err)
+		require.Equal(t, "kubectl", cmd)
+		require.Contains(t, args, "kustomize")
+		require.Contains(t, args, tempDir)
+		require.Contains(t, args, "--enable-helm")
+
+		t.Logf("kubectl fallback command: %s %s", cmd, strings.Join(args, " "))
+	})
+
+	// Test with real kustomize binary (should use kustomize directly)
+	t.Run("normal kustomize scenario", func(t *testing.T) {
+		runner := New(KustomizeBin("kustomize"))
+
+		buildArgs := []string{"-o", "/tmp/output.yaml", "build", "--enable-helm"}
+		cmd, args, err := runner.kustomizeBuildCommand(buildArgs, tempDir)
+		require.NoError(t, err)
+		require.Equal(t, "kustomize", cmd)
+		require.Equal(t, append(buildArgs, tempDir), args)
+
+		t.Logf("normal kustomize command: %s %s", cmd, strings.Join(args, " "))
+	})
+}

kustomize.go

@@ -17,6 +17,16 @@
 	Namespace  string           `yaml:"namespace"`
 }
 
+// KustomizationFile represents the structure of a kustomization.yaml file
+type KustomizationFile struct {
+	Resources  []string         `yaml:"resources,omitempty"`
+	Bases      []string         `yaml:"bases,omitempty"`
+	Images     []KustomizeImage `yaml:"images,omitempty"`
+	NamePrefix string           `yaml:"namePrefix,omitempty"`
+	NameSuffix string           `yaml:"nameSuffix,omitempty"`
+	Namespace  string           `yaml:"namespace,omitempty"`
+}
+
 type KustomizeImage struct {
 	Name    string `yaml:"name"`
 	NewName string `yaml:"newName"`
@@ -56,6 +66,28 @@
 	SetKustomizeBuildOption(opts *KustomizeBuildOpts) error
 }
 
+// generateKustomizationFile creates a complete kustomization.yaml content
+func (r *Runner) generateKustomizationFile(relPath string, opts KustomizeOpts) ([]byte, error) {
+	kustomization := KustomizationFile{
+		Resources: []string{relPath}, // Use resources instead of deprecated bases
+	}
+
+	if len(opts.Images) > 0 {
+		kustomization.Images = opts.Images
+	}
+	if opts.NamePrefix != "" {
+		kustomization.NamePrefix = opts.NamePrefix
+	}
+	if opts.NameSuffix != "" {
+		kustomization.NameSuffix = opts.NameSuffix
+	}
+	if opts.Namespace != "" {
+		kustomization.Namespace = opts.Namespace
+	}
+
+	return yaml.Marshal(&kustomization)
+}
+
 func (r *Runner) KustomizeBuild(srcDir string, tempDir string, opts ...KustomizeBuildOption) (string, error) {
 	kustomizeOpts := KustomizeOpts{}
 	u := &KustomizeBuildOpts{}
@@ -103,42 +135,18 @@
 	if err != nil {
 		return "", err
 	}
-	baseFile := []byte("bases:\n- " + relPath + "\n")
+
+	// Generate complete kustomization.yaml file directly instead of using edit commands
+	kustomizationContent, err := r.generateKustomizationFile(relPath, kustomizeOpts)
+	if err != nil {
+		return "", fmt.Errorf("generating kustomization.yaml: %v", err)
+	}
+
 	kustomizationPath := path.Join(tempDir, "kustomization.yaml")
-	if err := r.WriteFile(kustomizationPath, baseFile, 0644); err != nil {
+	if err := r.WriteFile(kustomizationPath, kustomizationContent, 0644); err != nil {
 		return "", err
 	}
 
-	if len(kustomizeOpts.Images) > 0 {
-		args := []string{"edit", "set", "image"}
-		for _, image := range kustomizeOpts.Images {
-			args = append(args, image.String())
-		}
-		_, err := r.runInDir(tempDir, r.kustomizeBin(), args...)
-		if err != nil {
-			return "", err
-		}
-	}
-	if kustomizeOpts.NamePrefix != "" {
-		_, err := r.runInDir(tempDir, r.kustomizeBin(), "edit", "set", "nameprefix", kustomizeOpts.NamePrefix)
-		if err != nil {
-			fmt.Println(err)
-			return "", err
-		}
-	}
-	if kustomizeOpts.NameSuffix != "" {
-		// "--" is there to avoid `namesuffix -acme` to fail due to `-a` being considered as a flag
-		_, err := r.runInDir(tempDir, r.kustomizeBin(), "edit", "set", "namesuffix", "--", kustomizeOpts.NameSuffix)
-		if err != nil {
-			return "", err
-		}
-	}
-	if kustomizeOpts.Namespace != "" {
-		_, err := r.runInDir(tempDir, r.kustomizeBin(), "edit", "set", "namespace", kustomizeOpts.Namespace)
-		if err != nil {
-			return "", err
-		}
-	}
 	outputFile := filepath.Join(tempDir, "templates", "kustomized.yaml")
 	kustomizeArgs := []string{"-o", outputFile, "build"}
 
@@ -159,7 +167,13 @@
 		kustomizeArgs = append(kustomizeArgs, "--helm-command="+u.HelmBinary)
 	}
 
-	out, err := r.runInDir(tempDir, r.kustomizeBin(), append(kustomizeArgs, tempDir)...)
+	// Use kubectl kustomize fallback if standalone kustomize is not available
+	buildCmd, buildArgs, err := r.kustomizeBuildCommand(kustomizeArgs, tempDir)
+	if err != nil {
+		return "", err
+	}
+
+	out, err := r.runInDir(tempDir, buildCmd, buildArgs...)
 	if err != nil {
 		return "", err
 	}
@@ -173,7 +187,13 @@
 }
 
 // kustomizeVersion returns the kustomize binary version.
+// Returns nil if kustomize binary is not available (fallback scenario).
 func (r *Runner) kustomizeVersion() (*semver.Version, error) {
+	// Skip version detection if using a fallback scenario
+	if !r.isKustomizeBinaryAvailable() {
+		return nil, nil
+	}
+
 	versionInfo, err := r.run(nil, r.kustomizeBin(), "version")
 	if err != nil {
 		return nil, err
@@ -193,12 +213,14 @@
 // kustomizeEnableAlphaPluginsFlag returns the kustomize binary alpha plugin argument.
 // Above Kustomize v3, it is `--enable-alpha-plugins`.
 // Below Kustomize v3 (including v3), it is `--enable_alpha_plugins`.
+// Uses modern flag format when kustomize binary is not available (kubectl fallback).
 func (r *Runner) kustomizeEnableAlphaPluginsFlag() (string, error) {
 	version, err := r.kustomizeVersion()
 	if err != nil {
 		return "", err
 	}
-	if version.Major() > 3 {
+	// If version is nil (fallback scenario), use modern flag format
+	if version == nil || version.Major() > 3 {
 		return "--enable-alpha-plugins", nil
 	}
 	return "--enable_alpha_plugins", nil
@@ -208,12 +230,14 @@
 // the root argument.
 // Above Kustomize v3, it is `--load-restrictor=LoadRestrictionsNone`.
 // Below Kustomize v3 (including v3), it is `--load_restrictor=none`.
+// Uses modern flag format when kustomize binary is not available (kubectl fallback).
 func (r *Runner) kustomizeLoadRestrictionsNoneFlag() (string, error) {
 	version, err := r.kustomizeVersion()
 	if err != nil {
 		return "", err
 	}
-	if version.Major() > 3 {
+	// If version is nil (fallback scenario), use modern flag format
+	if version == nil || version.Major() > 3 {
 		return "--load-restrictor=LoadRestrictionsNone", nil
 	}
 	return "--load_restrictor=none", nil

runner.go

@@ -103,6 +103,44 @@
 	return "kustomize"
 }
 
+// isKustomizeBinaryAvailable checks if the kustomize binary is available
+func (r *Runner) isKustomizeBinaryAvailable() bool {
+	_, _, err := r.captureBytes(r.kustomizeBin(), []string{"version"}, "", nil)
+	return err == nil
+}
+
+// kustomizeBuildCommand returns the appropriate command and args for kustomize build operation
+// Falls back to "kubectl kustomize" if standalone kustomize binary is not available
+func (r *Runner) kustomizeBuildCommand(buildArgs []string, targetDir string) (string, []string, error) {
+	// First check if the configured kustomize binary is available
+	if r.isKustomizeBinaryAvailable() {
+		return r.kustomizeBin(), append(buildArgs, targetDir), nil
+	}
+
+	// Fallback to kubectl kustomize
+	// kubectl kustomize requires different argument order: kubectl kustomize [flags] DIR
+	// We need to transform: kustomize [args] build [more-args] DIR
+	// Into: kubectl kustomize [more-args] DIR
+
+	kubectlArgs := []string{"kustomize"}
+
+	// Extract build-specific flags from buildArgs (everything except "build")
+	for i, arg := range buildArgs {
+		if arg == "build" {
+			// Add everything after "build" except the target dir (which gets added at the end)
+			kubectlArgs = append(kubectlArgs, buildArgs[i+1:]...)
+			break
+		}
+		// Add everything before "build"
+		kubectlArgs = append(kubectlArgs, arg)
+	}
+
+	// Add target directory at the end
+	kubectlArgs = append(kubectlArgs, targetDir)
+
+	return "kubectl", kubectlArgs, nil
+}
+
 func (r *Runner) run(envs map[string]string, cmd string, args ...string) (string, error) {
 	bytes, err := r.runBytes(envs, "", cmd, args...)