fix(kustomize): Updated generator support for both EnvSources and FileSources using [{key}=]{path} syntax

pkg/skaffold/deploy/kubectl/kustomize_test.go

@@ -360,6 +360,16 @@ func TestDependenciesForKustomization(t *testing.T) {
 - envs: [secret2.env, secret3.env]`},
 			expected: []string{"kustomization.yaml", "secret1.env", "secret1.file", "secret2.env", "secret2.file", "secret3.env", "secret3.file"},
 		},
+		{
+			description: "configMapGenerator & secretGenerator listing file sources with alternative keys",
+			kustomizations: map[string]string{"kustomization.yaml": `configMapGenerator:
+- name: config-sample
+  files: [app.properties=app.local.properties]
+secretGenerator:
+- name: secret-sample
+  files: [secrets.json=secrets.local.json]`},
+			expected: []string{"app.local.properties", "kustomization.yaml", "secrets.local.json"},
+		},
 		{
 			description:    "base exists locally",
 			kustomizations: map[string]string{"kustomization.yaml": `bases: [base]`},

pkg/skaffold/render/renderer/kustomize/fs.go

@@ -62,7 +62,7 @@ func (f TmpFSReal) GetPath(path string) (string, error) {
 }
 
 func (f TmpFSReal) validate(path string) error {
-	if path != f.root && !strings.HasPrefix(path, f.root+"/") {
+	if path != f.root && !strings.HasPrefix(path, f.root+string(filepath.Separator)) {
 		return fmt.Errorf("temporary file system operation is out of boundary, root: %s, trying to access %s", f.root, path)
 	}
 	return nil

pkg/skaffold/render/renderer/kustomize/kustomize.go

@@ -130,7 +130,7 @@ func (k Kustomize) render(ctx context.Context, kustomizePath string, useKubectlK
 		defer fs.Cleanup()
 
 		if err := k.mirror(kustomizePath, fs); err == nil {
-			kustomizePath = filepath.Join(temp, kustomizePath)
+			kustomizePath = filepath.Join(temp, strings.TrimPrefix(kustomizePath, filepath.VolumeName(kustomizePath)))
 		} else {
 			return out, err
 		}
@@ -167,7 +167,9 @@ func (k Kustomize) mirror(kusDir string, fs TmpFS) error {
 		return err
 	}
 
-	if err := fs.WriteTo(kFile, bytes); err != nil {
+	pFile := strings.TrimPrefix(kFile, filepath.VolumeName(kFile))
+
+	if err := fs.WriteTo(pFile, bytes); err != nil {
 		return err
 	}
 
@@ -314,15 +316,18 @@ func (k Kustomize) mirrorFile(kusDir string, fs TmpFS, path string) error {
 	if sUtil.IsURL(path) {
 		return nil
 	}
-	pFile := filepath.Join(kusDir, path)
-	bytes, err := os.ReadFile(pFile)
+
+	sourceFile := filepath.Join(kusDir, path)
+	targetFile := strings.TrimPrefix(sourceFile, filepath.VolumeName(sourceFile))
+
+	bytes, err := os.ReadFile(sourceFile)
 	if err != nil {
 		return err
 	}
-	if err := fs.WriteTo(pFile, bytes); err != nil {
+	if err := fs.WriteTo(targetFile, bytes); err != nil {
 		return err
 	}
-	fsPath, err := fs.GetPath(pFile)
+	fsPath, err := fs.GetPath(targetFile)
 
 	if err != nil {
 		return err
@@ -336,7 +341,7 @@ func (k Kustomize) mirrorFile(kusDir string, fs TmpFS, path string) error {
 
 		err = k.applySetters.ApplyPath(fsPath)
 		if err != nil {
-			return fmt.Errorf("failed to apply setter to file %s, err: %v", pFile, err)
+			return fmt.Errorf("failed to apply setter to file %s, err: %v", sourceFile, err)
 		}
 	}
 	return nil
@@ -401,6 +406,18 @@ func (k Kustomize) mirrorSecretGenerators(kusDir string, fs TmpFS, args []types.
 	for _, arg := range args {
 		if arg.FileSources != nil {
 			for _, f := range arg.FileSources {
+				// Entries from FileSources can take the form: [{key}=]{path}
+				i := strings.IndexRune(f, '=')
+				if i > -1 {
+					f = f[i+1:]
+				}
+				if err := k.mirrorFile(kusDir, fs, f); err != nil {
+					return err
+				}
+			}
+		}
+		if arg.EnvSources != nil {
+			for _, f := range arg.EnvSources {
 				if err := k.mirrorFile(kusDir, fs, f); err != nil {
 					return err
 				}
@@ -414,6 +431,18 @@ func (k Kustomize) mirrorConfigMapGenerators(kusDir string, fs TmpFS, args []typ
 	for _, arg := range args {
 		if arg.FileSources != nil {
 			for _, f := range arg.FileSources {
+				// Entries from FileSources can take the form: [{key}=]{path}
+				i := strings.IndexRune(f, '=')
+				if i > -1 {
+					f = f[i+1:]
+				}
+				if err := k.mirrorFile(kusDir, fs, f); err != nil {
+					return err
+				}
+			}
+		}
+		if arg.EnvSources != nil {
+			for _, f := range arg.EnvSources {
 				if err := k.mirrorFile(kusDir, fs, f); err != nil {
 					return err
 				}
@@ -524,21 +553,47 @@ func DependenciesForKustomization(dir string) ([]string, error) {
 	}
 
 	for _, generator := range content.ConfigMapGenerator {
-		deps = append(deps, sUtil.AbsolutePaths(dir, generator.FileSources)...)
-		envs := generator.EnvSources
+		var sources []string
+
+		if generator.FileSources != nil {
+			for _, f := range generator.FileSources {
+				// Entries from FileSources can take the form: [{key}=]{path}
+				i := strings.IndexRune(f, '=')
+				if i > -1 {
+					f = f[i+1:]
+				}
+				sources = append(sources, f)
+			}
+		}
+
+		sources = append(sources, generator.EnvSources...)
 		if generator.EnvSource != "" {
-			envs = append(envs, generator.EnvSource)
+			sources = append(sources, generator.EnvSource)
 		}
-		deps = append(deps, sUtil.AbsolutePaths(dir, envs)...)
+
+		deps = append(deps, sUtil.AbsolutePaths(dir, sources)...)
 	}
 
 	for _, generator := range content.SecretGenerator {
-		deps = append(deps, sUtil.AbsolutePaths(dir, generator.FileSources)...)
-		envs := generator.EnvSources
+		var sources []string
+
+		if generator.FileSources != nil {
+			for _, f := range generator.FileSources {
+				// Entries from FileSources can take the form: [{key}=]{path}
+				i := strings.IndexRune(f, '=')
+				if i > -1 {
+					f = f[i+1:]
+				}
+				sources = append(sources, f)
+			}
+		}
+
+		sources = append(sources, generator.EnvSources...)
 		if generator.EnvSource != "" {
-			envs = append(envs, generator.EnvSource)
+			sources = append(sources, generator.EnvSource)
 		}
-		deps = append(deps, sUtil.AbsolutePaths(dir, envs)...)
+
+		deps = append(deps, sUtil.AbsolutePaths(dir, sources)...)
 	}
 
 	return deps, nil

pkg/skaffold/render/renderer/kustomize/kustomize_test.go

@@ -17,8 +17,13 @@ limitations under the License.
 package kustomize
 
 import (
+	"path/filepath"
+	"slices"
+	"strings"
 	"testing"
 
+	"github.com/GoogleContainerTools/skaffold/v2/pkg/skaffold/render"
+	"github.com/GoogleContainerTools/skaffold/v2/pkg/skaffold/schema/latest"
 	"github.com/GoogleContainerTools/skaffold/v2/testutil"
 )
 
@@ -86,3 +91,116 @@ func TestBuildCommandArgs(t *testing.T) {
 		})
 	}
 }
+
+func TestMirror(t *testing.T) {
+	tests := []struct {
+		description string
+		shouldErr   bool
+		createFiles map[string]string
+		touchFiles  []string
+	}{
+		{
+			description: "mirror configmap and secret generators using env files, regular files, and regular files with keys",
+			shouldErr:   false,
+			createFiles: map[string]string{
+				"kustomization.yaml": `configMapGenerator:
+  - name: app-env
+    envs:
+      - configmaps/app-env/app.env
+  - name: app-config
+    files:
+      - credentials.pub=configmaps/app-config/credentials.local.pub
+      - configmaps/app-config/setup.json
+
+secretGenerator:
+  - name: app-env-secrets
+    envs:
+      - secrets/app-env-secrets/secrets.env
+  - name: app-config-secrets
+    files:
+      - credentials.key=secrets/app-config-secrets/credentials.local.key
+      - secrets/app-config-secrets/eyesonly.txt
+`},
+			touchFiles: []string{
+				"configmaps/app-env/app.env",
+				"configmaps/app-config/credentials.local.pub",
+				"configmaps/app-config/setup.json",
+				"secrets/app-env-secrets/secrets.env",
+				"secrets/app-config-secrets/credentials.local.key",
+				"secrets/app-config-secrets/eyesonly.txt",
+			},
+		},
+	}
+
+	for _, test := range tests {
+		testutil.Run(t, test.description, func(t *testutil.T) {
+			// Create the file structure required for the test
+			sourceDir := t.NewTempDir()
+
+			for path, contents := range test.createFiles {
+				sourceDir.Write(path, contents)
+			}
+
+			sourceDir.Touch(test.touchFiles...)
+
+			// Create the instance to test
+			mockCfg := render.MockConfig{
+				WorkingDir: sourceDir.Root(),
+			}
+
+			rc := latest.RenderConfig{
+				Generate: latest.Generate{
+					Kustomize: &latest.Kustomize{
+						Paths: []string{sourceDir.Root()},
+					},
+				},
+			}
+
+			k, err := New(mockCfg, rc, map[string]string{}, "default", "", nil, false)
+			t.CheckNoError(err)
+
+			// Test the mirror function on a temporary workspace
+			targetDir := t.NewTempDir()
+			fs := newTmpFS(targetDir.Root())
+			defer fs.Cleanup()
+
+			t_err := k.mirror(sourceDir.Root(), fs)
+
+			// Gather a list of the expected files
+			var expectedFiles []string
+
+			sourceFileList, err := sourceDir.List()
+			t.CheckNoError(err)
+
+			sourceVolName := filepath.VolumeName(sourceDir.Root())
+			if sourceVolName != "" {
+				for _, f := range sourceFileList {
+					expectedFiles = append(expectedFiles, strings.TrimPrefix(f, sourceVolName))
+				}
+			} else {
+				expectedFiles = sourceFileList
+			}
+
+			slices.Sort(expectedFiles)
+
+			// Gather a list of files that have been created by the mirror function
+			targetFileList, err := targetDir.List()
+			t.CheckNoError(err)
+
+			minPrefixLen := len(targetDir.Root()) + len(sourceDir.Root()) - len(sourceVolName)
+			prefixLen := len(targetDir.Root())
+
+			var mirroredFiles []string
+			for _, f := range targetFileList {
+				if len(f) >= minPrefixLen {
+					mirroredFiles = append(mirroredFiles, f[prefixLen:])
+				}
+			}
+
+			slices.Sort(mirroredFiles)
+
+			// Validate test results
+			t.CheckErrorAndDeepEqual(test.shouldErr, t_err, expectedFiles, mirroredFiles)
+		})
+	}
+}