feat(bundler): Add kustomize bundler

pkg/bundler/kustomize_bundler.go

@@ -0,0 +1,74 @@
+package bundler
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+)
+
+// The KustomizeBundler handles bundling of kustomize manifests and related files.
+// It copies all files from the kustomize directory to the artifact build directory.
+// The KustomizeBundler ensures that all kustomize resources are properly bundled
+// for distribution with the artifact for use with Flux OCIRegistry.
+
+// =============================================================================
+// Types
+// =============================================================================
+
+// KustomizeBundler handles bundling of kustomize files
+type KustomizeBundler struct {
+	BaseBundler
+}
+
+// =============================================================================
+// Constructor
+// =============================================================================
+
+// NewKustomizeBundler creates a new KustomizeBundler instance
+func NewKustomizeBundler() *KustomizeBundler {
+	return &KustomizeBundler{
+		BaseBundler: *NewBaseBundler(),
+	}
+}
+
+// =============================================================================
+// Public Methods
+// =============================================================================
+
+// Bundle adds all files from kustomize directory to the artifact by recursively walking the directory tree.
+// It validates that the kustomize directory exists, then walks through all files preserving the directory structure.
+// Each file is read and added to the artifact maintaining the original kustomize path structure.
+// Directories are skipped and only regular files are processed for bundling.
+func (k *KustomizeBundler) Bundle(artifact Artifact) error {
+	kustomizeSource := "kustomize"
+
+	if _, err := k.shims.Stat(kustomizeSource); os.IsNotExist(err) {
+		return fmt.Errorf("kustomize directory not found: %s", kustomizeSource)
+	}
+
+	return k.shims.Walk(kustomizeSource, func(path string, info os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+
+		if info.IsDir() {
+			return nil
+		}
+
+		relPath, err := k.shims.FilepathRel(kustomizeSource, path)
+		if err != nil {
+			return fmt.Errorf("failed to get relative path: %w", err)
+		}
+
+		data, err := k.shims.ReadFile(path)
+		if err != nil {
+			return fmt.Errorf("failed to read kustomize file %s: %w", path, err)
+		}
+
+		artifactPath := "kustomize/" + filepath.ToSlash(relPath)
+		return artifact.AddFile(artifactPath, data)
+	})
+}
+
+// Ensure KustomizeBundler implements Bundler interface
+var _ Bundler = (*KustomizeBundler)(nil)