Reproducible chart archive builds

Building the same chart into an archive multiple times will have
the same sha256 hash.

Perviously, the time in the headers for a file was time.Now() which
changed each time. The time is now collected from the operating
system when the file is loaded and this time is used.

Fixes: #3612

Signed-off-by: Matt Farina <matt.farina@suse.com>

internal/chart/v3/chart.go

@@ -19,6 +19,7 @@ import (
 	"path/filepath"
 	"regexp"
 	"strings"
+	"time"
 
 	"helm.sh/helm/v4/pkg/chart/common"
 )
@@ -47,9 +48,13 @@ type Chart struct {
 	Values map[string]interface{} `json:"values"`
 	// Schema is an optional JSON schema for imposing structure on Values
 	Schema []byte `json:"schema"`
+	// SchemaModTime the schema was last modified
+	SchemaModTime time.Time `json:"schemamodtime,omitempty"`
 	// Files are miscellaneous files in a chart archive,
 	// e.g. README, LICENSE, etc.
 	Files []*common.File `json:"files"`
+	// ModTime the chart metadata was last modified
+	ModTime time.Time `json:"modtime,omitzero"`
 
 	parent       *Chart
 	dependencies []*Chart

internal/chart/v3/chart_test.go

@@ -18,6 +18,7 @@ package v3
 import (
 	"encoding/json"
 	"testing"
+	"time"
 
 	"github.com/stretchr/testify/assert"
 
@@ -25,27 +26,33 @@ import (
 )
 
 func TestCRDs(t *testing.T) {
+	modTime := time.Now()
 	chrt := Chart{
 		Files: []*common.File{
 			{
-				Name: "crds/foo.yaml",
-				Data: []byte("hello"),
+				Name:    "crds/foo.yaml",
+				ModTime: modTime,
+				Data:    []byte("hello"),
 			},
 			{
-				Name: "bar.yaml",
-				Data: []byte("hello"),
+				Name:    "bar.yaml",
+				ModTime: modTime,
+				Data:    []byte("hello"),
 			},
 			{
-				Name: "crds/foo/bar/baz.yaml",
-				Data: []byte("hello"),
+				Name:    "crds/foo/bar/baz.yaml",
+				ModTime: modTime,
+				Data:    []byte("hello"),
 			},
 			{
-				Name: "crdsfoo/bar/baz.yaml",
-				Data: []byte("hello"),
+				Name:    "crdsfoo/bar/baz.yaml",
+				ModTime: modTime,
+				Data:    []byte("hello"),
 			},
 			{
-				Name: "crds/README.md",
-				Data: []byte("# hello"),
+				Name:    "crds/README.md",
+				ModTime: modTime,
+				Data:    []byte("# hello"),
 			},
 		},
 	}
@@ -61,8 +68,9 @@ func TestSaveChartNoRawData(t *testing.T) {
 	chrt := Chart{
 		Raw: []*common.File{
 			{
-				Name: "fhqwhgads.yaml",
-				Data: []byte("Everybody to the Limit"),
+				Name:    "fhqwhgads.yaml",
+				ModTime: time.Now(),
+				Data:    []byte("Everybody to the Limit"),
 			},
 		},
 	}
@@ -163,27 +171,33 @@ func TestChartFullPath(t *testing.T) {
 }
 
 func TestCRDObjects(t *testing.T) {
+	modTime := time.Now()
 	chrt := Chart{
 		Files: []*common.File{
 			{
-				Name: "crds/foo.yaml",
-				Data: []byte("hello"),
+				Name:    "crds/foo.yaml",
+				ModTime: modTime,
+				Data:    []byte("hello"),
 			},
 			{
-				Name: "bar.yaml",
-				Data: []byte("hello"),
+				Name:    "bar.yaml",
+				ModTime: modTime,
+				Data:    []byte("hello"),
 			},
 			{
-				Name: "crds/foo/bar/baz.yaml",
-				Data: []byte("hello"),
+				Name:    "crds/foo/bar/baz.yaml",
+				ModTime: modTime,
+				Data:    []byte("hello"),
 			},
 			{
-				Name: "crdsfoo/bar/baz.yaml",
-				Data: []byte("hello"),
+				Name:    "crdsfoo/bar/baz.yaml",
+				ModTime: modTime,
+				Data:    []byte("hello"),
 			},
 			{
-				Name: "crds/README.md",
-				Data: []byte("# hello"),
+				Name:    "crds/README.md",
+				ModTime: modTime,
+				Data:    []byte("# hello"),
 			},
 		},
 	}
@@ -193,16 +207,18 @@ func TestCRDObjects(t *testing.T) {
 			Name:     "crds/foo.yaml",
 			Filename: "crds/foo.yaml",
 			File: &common.File{
-				Name: "crds/foo.yaml",
-				Data: []byte("hello"),
+				Name:    "crds/foo.yaml",
+				ModTime: modTime,
+				Data:    []byte("hello"),
 			},
 		},
 		{
 			Name:     "crds/foo/bar/baz.yaml",
 			Filename: "crds/foo/bar/baz.yaml",
 			File: &common.File{
-				Name: "crds/foo/bar/baz.yaml",
-				Data: []byte("hello"),
+				Name:    "crds/foo/bar/baz.yaml",
+				ModTime: modTime,
+				Data:    []byte("hello"),
 			},
 		},
 	}

internal/chart/v3/lint/rules/template_test.go

@@ -22,6 +22,7 @@ import (
 	"path/filepath"
 	"strings"
 	"testing"
+	"time"
 
 	chart "helm.sh/helm/v4/internal/chart/v3"
 	"helm.sh/helm/v4/internal/chart/v3/lint/support"
@@ -183,6 +184,7 @@ func TestValidateMetadataName(t *testing.T) {
 }
 
 func TestDeprecatedAPIFails(t *testing.T) {
+	modTime := time.Now()
 	mychart := chart.Chart{
 		Metadata: &chart.Metadata{
 			APIVersion: "v2",
@@ -192,12 +194,14 @@ func TestDeprecatedAPIFails(t *testing.T) {
 		},
 		Templates: []*common.File{
 			{
-				Name: "templates/baddeployment.yaml",
-				Data: []byte("apiVersion: apps/v1beta1\nkind: Deployment\nmetadata:\n  name: baddep\nspec: {selector: {matchLabels: {foo: bar}}}"),
+				Name:    "templates/baddeployment.yaml",
+				ModTime: modTime,
+				Data:    []byte("apiVersion: apps/v1beta1\nkind: Deployment\nmetadata:\n  name: baddep\nspec: {selector: {matchLabels: {foo: bar}}}"),
 			},
 			{
-				Name: "templates/goodsecret.yaml",
-				Data: []byte("apiVersion: v1\nkind: Secret\nmetadata:\n  name: goodsecret"),
+				Name:    "templates/goodsecret.yaml",
+				ModTime: modTime,
+				Data:    []byte("apiVersion: v1\nkind: Secret\nmetadata:\n  name: goodsecret"),
 			},
 		},
 	}
@@ -252,8 +256,9 @@ func TestStrictTemplateParsingMapError(t *testing.T) {
 		},
 		Templates: []*common.File{
 			{
-				Name: "templates/configmap.yaml",
-				Data: []byte(manifest),
+				Name:    "templates/configmap.yaml",
+				ModTime: time.Now(),
+				Data:    []byte(manifest),
 			},
 		},
 	}
@@ -381,8 +386,9 @@ func TestEmptyWithCommentsManifests(t *testing.T) {
 		},
 		Templates: []*common.File{
 			{
-				Name: "templates/empty-with-comments.yaml",
-				Data: []byte("#@formatter:off\n"),
+				Name:    "templates/empty-with-comments.yaml",
+				ModTime: time.Now(),
+				Data:    []byte("#@formatter:off\n"),
 			},
 		},
 	}

internal/chart/v3/loader/directory.go

@@ -111,7 +111,7 @@ func LoadDir(dir string) (*chart.Chart, error) {
 
 		data = bytes.TrimPrefix(data, utf8bom)
 
-		files = append(files, &archive.BufferedFile{Name: n, Data: data})
+		files = append(files, &archive.BufferedFile{Name: n, ModTime: fi.ModTime(), Data: data})
 		return nil
 	}
 	if err = sympath.Walk(topdir, walk); err != nil {

internal/chart/v3/loader/load.go

@@ -25,6 +25,7 @@ import (
 	"maps"
 	"os"
 	"path/filepath"
+	"slices"
 	"strings"
 
 	utilyaml "k8s.io/apimachinery/pkg/util/yaml"
@@ -71,11 +72,12 @@ func Load(name string) (*chart.Chart, error) {
 func LoadFiles(files []*archive.BufferedFile) (*chart.Chart, error) {
 	c := new(chart.Chart)
 	subcharts := make(map[string][]*archive.BufferedFile)
+	var subChartsKeys []string
 
 	// do not rely on assumed ordering of files in the chart and crash
 	// if Chart.yaml was not coming early enough to initialize metadata
 	for _, f := range files {
-		c.Raw = append(c.Raw, &common.File{Name: f.Name, Data: f.Data})
+		c.Raw = append(c.Raw, &common.File{Name: f.Name, ModTime: f.ModTime, Data: f.Data})
 		if f.Name == "Chart.yaml" {
 			if c.Metadata == nil {
 				c.Metadata = new(chart.Metadata)
@@ -89,6 +91,7 @@ func LoadFiles(files []*archive.BufferedFile) (*chart.Chart, error) {
 			if c.Metadata.APIVersion == "" {
 				c.Metadata.APIVersion = chart.APIVersionV3
 			}
+			c.ModTime = f.ModTime
 		}
 	}
 	for _, f := range files {
@@ -109,20 +112,24 @@ func LoadFiles(files []*archive.BufferedFile) (*chart.Chart, error) {
 			c.Values = values
 		case f.Name == "values.schema.json":
 			c.Schema = f.Data
+			c.SchemaModTime = f.ModTime
 
 		case strings.HasPrefix(f.Name, "templates/"):
-			c.Templates = append(c.Templates, &common.File{Name: f.Name, Data: f.Data})
+			c.Templates = append(c.Templates, &common.File{Name: f.Name, Data: f.Data, ModTime: f.ModTime})
 		case strings.HasPrefix(f.Name, "charts/"):
 			if filepath.Ext(f.Name) == ".prov" {
-				c.Files = append(c.Files, &common.File{Name: f.Name, Data: f.Data})
+				c.Files = append(c.Files, &common.File{Name: f.Name, Data: f.Data, ModTime: f.ModTime})
 				continue
 			}
 
 			fname := strings.TrimPrefix(f.Name, "charts/")
 			cname := strings.SplitN(fname, "/", 2)[0]
-			subcharts[cname] = append(subcharts[cname], &archive.BufferedFile{Name: fname, Data: f.Data})
+			if slices.Index(subChartsKeys, cname) == -1 {
+				subChartsKeys = append(subChartsKeys, cname)
+			}
+			subcharts[cname] = append(subcharts[cname], &archive.BufferedFile{Name: fname, ModTime: f.ModTime, Data: f.Data})
 		default:
-			c.Files = append(c.Files, &common.File{Name: f.Name, Data: f.Data})
+			c.Files = append(c.Files, &common.File{Name: f.Name, ModTime: f.ModTime, Data: f.Data})
 		}
 	}
 

internal/chart/v3/loader/load_test.go

@@ -184,9 +184,11 @@ func TestLoadFile(t *testing.T) {
 }
 
 func TestLoadFiles(t *testing.T) {
+	modTime := time.Now()
 	goodFiles := []*archive.BufferedFile{
 		{
-			Name: "Chart.yaml",
+			Name:    "Chart.yaml",
+			ModTime: modTime,
 			Data: []byte(`apiVersion: v3
 name: frobnitz
 description: This is a frobnitz.
@@ -207,20 +209,24 @@ icon: https://example.com/64x64.png
 `),
 		},
 		{
-			Name: "values.yaml",
-			Data: []byte("var: some values"),
+			Name:    "values.yaml",
+			ModTime: modTime,
+			Data:    []byte("var: some values"),
 		},
 		{
-			Name: "values.schema.json",
-			Data: []byte("type: Values"),
+			Name:    "values.schema.json",
+			ModTime: modTime,
+			Data:    []byte("type: Values"),
 		},
 		{
-			Name: "templates/deployment.yaml",
-			Data: []byte("some deployment"),
+			Name:    "templates/deployment.yaml",
+			ModTime: modTime,
+			Data:    []byte("some deployment"),
 		},
 		{
-			Name: "templates/service.yaml",
-			Data: []byte("some service"),
+			Name:    "templates/service.yaml",
+			ModTime: modTime,
+			Data:    []byte("some service"),
 		},
 	}
 
@@ -260,26 +266,32 @@ icon: https://example.com/64x64.png
 // Test the order of file loading. The Chart.yaml file needs to come first for
 // later comparison checks. See https://github.com/helm/helm/pull/8948
 func TestLoadFilesOrder(t *testing.T) {
+	modTime := time.Now()
 	goodFiles := []*archive.BufferedFile{
 		{
-			Name: "requirements.yaml",
-			Data: []byte("dependencies:"),
+			Name:    "requirements.yaml",
+			ModTime: modTime,
+			Data:    []byte("dependencies:"),
 		},
 		{
-			Name: "values.yaml",
-			Data: []byte("var: some values"),
+			Name:    "values.yaml",
+			ModTime: modTime,
+			Data:    []byte("var: some values"),
 		},
 
 		{
-			Name: "templates/deployment.yaml",
-			Data: []byte("some deployment"),
+			Name:    "templates/deployment.yaml",
+			ModTime: modTime,
+			Data:    []byte("some deployment"),
 		},
 		{
-			Name: "templates/service.yaml",
-			Data: []byte("some service"),
+			Name:    "templates/service.yaml",
+			ModTime: modTime,
+			Data:    []byte("some service"),
 		},
 		{
-			Name: "Chart.yaml",
+			Name:    "Chart.yaml",
+			ModTime: modTime,
 			Data: []byte(`apiVersion: v3
 name: frobnitz
 description: This is a frobnitz.

internal/chart/v3/util/create.go

@@ -660,7 +660,7 @@ func CreateFrom(chartfile *chart.Metadata, dest, src string) error {
 
 	for _, template := range schart.Templates {
 		newData := transform(string(template.Data), schart.Name())
-		updatedTemplates = append(updatedTemplates, &common.File{Name: template.Name, Data: newData})
+		updatedTemplates = append(updatedTemplates, &common.File{Name: template.Name, ModTime: template.ModTime, Data: newData})
 	}
 
 	schart.Templates = updatedTemplates

internal/chart/v3/util/save.go

@@ -166,7 +166,7 @@ func writeTarContents(out *tar.Writer, c *chart.Chart, prefix string) error {
 	if err != nil {
 		return err
 	}
-	if err := writeToTar(out, filepath.Join(base, ChartfileName), cdata); err != nil {
+	if err := writeToTar(out, filepath.Join(base, ChartfileName), cdata, c.ModTime); err != nil {
 		return err
 	}
 
@@ -176,7 +176,7 @@ func writeTarContents(out *tar.Writer, c *chart.Chart, prefix string) error {
 		if err != nil {
 			return err
 		}
-		if err := writeToTar(out, filepath.Join(base, "Chart.lock"), ldata); err != nil {
+		if err := writeToTar(out, filepath.Join(base, "Chart.lock"), ldata, c.Lock.Generated); err != nil {
 			return err
 		}
 	}
@@ -184,7 +184,7 @@ func writeTarContents(out *tar.Writer, c *chart.Chart, prefix string) error {
 	// Save values.yaml
 	for _, f := range c.Raw {
 		if f.Name == ValuesfileName {
-			if err := writeToTar(out, filepath.Join(base, ValuesfileName), f.Data); err != nil {
+			if err := writeToTar(out, filepath.Join(base, ValuesfileName), f.Data, f.ModTime); err != nil {
 				return err
 			}
 		}
@@ -195,7 +195,7 @@ func writeTarContents(out *tar.Writer, c *chart.Chart, prefix string) error {
 		if !json.Valid(c.Schema) {
 			return errors.New("invalid JSON in " + SchemafileName)
 		}
-		if err := writeToTar(out, filepath.Join(base, SchemafileName), c.Schema); err != nil {
+		if err := writeToTar(out, filepath.Join(base, SchemafileName), c.Schema, c.SchemaModTime); err != nil {
 			return err
 		}
 	}
@@ -203,7 +203,7 @@ func writeTarContents(out *tar.Writer, c *chart.Chart, prefix string) error {
 	// Save templates
 	for _, f := range c.Templates {
 		n := filepath.Join(base, f.Name)
-		if err := writeToTar(out, n, f.Data); err != nil {
+		if err := writeToTar(out, n, f.Data, f.ModTime); err != nil {
 			return err
 		}
 	}
@@ -211,7 +211,7 @@ func writeTarContents(out *tar.Writer, c *chart.Chart, prefix string) error {
 	// Save files
 	for _, f := range c.Files {
 		n := filepath.Join(base, f.Name)
-		if err := writeToTar(out, n, f.Data); err != nil {
+		if err := writeToTar(out, n, f.Data, f.ModTime); err != nil {
 			return err
 		}
 	}
@@ -226,13 +226,13 @@ func writeTarContents(out *tar.Writer, c *chart.Chart, prefix string) error {
 }
 
 // writeToTar writes a single file to a tar archive.
-func writeToTar(out *tar.Writer, name string, body []byte) error {
+func writeToTar(out *tar.Writer, name string, body []byte, modTime time.Time) error {
 	// TODO: Do we need to create dummy parent directory names if none exist?
 	h := &tar.Header{
 		Name:    filepath.ToSlash(name),
 		Mode:    0644,
 		Size:    int64(len(body)),
-		ModTime: time.Now(),
+		ModTime: modTime,
 	}
 	if err := out.WriteHeader(h); err != nil {
 		return err

internal/chart/v3/util/save_test.go

@@ -20,6 +20,8 @@ import (
 	"archive/tar"
 	"bytes"
 	"compress/gzip"
+	"crypto/sha256"
+	"fmt"
 	"io"
 	"os"
 	"path"
@@ -49,7 +51,7 @@ func TestSave(t *testing.T) {
 					Digest: "testdigest",
 				},
 				Files: []*common.File{
-					{Name: "scheherazade/shahryar.txt", Data: []byte("1,001 Nights")},
+					{Name: "scheherazade/shahryar.txt", ModTime: time.Now(), Data: []byte("1,001 Nights")},
 				},
 				Schema: []byte("{\n  \"title\": \"Values\"\n}"),
 			}
@@ -115,7 +117,7 @@ func TestSave(t *testing.T) {
 			Digest: "testdigest",
 		},
 		Files: []*common.File{
-			{Name: "scheherazade/shahryar.txt", Data: []byte("1,001 Nights")},
+			{Name: "scheherazade/shahryar.txt", ModTime: time.Now(), Data: []byte("1,001 Nights")},
 		},
 	}
 	_, err := Save(c, tmp)
@@ -141,7 +143,6 @@ func TestSavePreservesTimestamps(t *testing.T) {
 	// check will fail because `initialCreateTime` will be identical to the
 	// written timestamp for the files.
 	initialCreateTime := time.Now().Add(-1 * time.Second)
-
 	tmp := t.TempDir()
 
 	c := &chart.Chart{
@@ -150,14 +151,16 @@ func TestSavePreservesTimestamps(t *testing.T) {
 			Name:       "ahab",
 			Version:    "1.2.3",
 		},
+		ModTime: initialCreateTime,
 		Values: map[string]interface{}{
 			"imageName": "testimage",
 			"imageId":   42,
 		},
 		Files: []*common.File{
-			{Name: "scheherazade/shahryar.txt", Data: []byte("1,001 Nights")},
+			{Name: "scheherazade/shahryar.txt", ModTime: initialCreateTime, Data: []byte("1,001 Nights")},
 		},
-		Schema: []byte("{\n  \"title\": \"Values\"\n}"),
+		Schema:        []byte("{\n  \"title\": \"Values\"\n}"),
+		SchemaModTime: initialCreateTime,
 	}
 
 	where, err := Save(c, tmp)
@@ -170,8 +173,9 @@ func TestSavePreservesTimestamps(t *testing.T) {
 		t.Fatalf("Failed to parse tar: %v", err)
 	}
 
+	roundedTime := initialCreateTime.Round(time.Second)
 	for _, header := range allHeaders {
-		if header.ModTime.Before(initialCreateTime) {
+		if !header.ModTime.Equal(roundedTime) {
 			t.Fatalf("File timestamp not preserved: %v", header.ModTime)
 		}
 	}
@@ -213,6 +217,7 @@ func retrieveAllHeadersFromTar(path string) ([]*tar.Header, error) {
 
 func TestSaveDir(t *testing.T) {
 	tmp := t.TempDir()
+	modTime := time.Now()
 
 	c := &chart.Chart{
 		Metadata: &chart.Metadata{
@@ -221,10 +226,10 @@ func TestSaveDir(t *testing.T) {
 			Version:    "1.2.3",
 		},
 		Files: []*common.File{
-			{Name: "scheherazade/shahryar.txt", Data: []byte("1,001 Nights")},
+			{Name: "scheherazade/shahryar.txt", ModTime: modTime, Data: []byte("1,001 Nights")},
 		},
 		Templates: []*common.File{
-			{Name: path.Join(TemplatesDir, "nested", "dir", "thing.yaml"), Data: []byte("abc: {{ .Values.abc }}")},
+			{Name: path.Join(TemplatesDir, "nested", "dir", "thing.yaml"), ModTime: modTime, Data: []byte("abc: {{ .Values.abc }}")},
 		},
 	}
 
@@ -260,3 +265,90 @@ func TestSaveDir(t *testing.T) {
 		t.Fatalf("Did not get expected error for chart named %q", c.Name())
 	}
 }
+
+func TestRepeatableSave(t *testing.T) {
+	tmp := t.TempDir()
+	defer os.RemoveAll(tmp)
+	modTime := time.Date(2021, 9, 1, 20, 34, 58, 651387237, time.UTC)
+	tests := []struct {
+		name  string
+		chart *chart.Chart
+		want  string
+	}{
+		{
+			name: "Package 1 file",
+			chart: &chart.Chart{
+				Metadata: &chart.Metadata{
+					APIVersion: chart.APIVersionV3,
+					Name:       "ahab",
+					Version:    "1.2.3",
+				},
+				ModTime: modTime,
+				Lock: &chart.Lock{
+					Digest: "testdigest",
+				},
+				Files: []*common.File{
+					{Name: "scheherazade/shahryar.txt", ModTime: modTime, Data: []byte("1,001 Nights")},
+				},
+				Schema:        []byte("{\n  \"title\": \"Values\"\n}"),
+				SchemaModTime: modTime,
+			},
+			want: "bcb52ba7b7c2801be84cdc96d395f00749896a4679a7c9deacdfe934d0c49c1b",
+		},
+		{
+			name: "Package 2 files",
+			chart: &chart.Chart{
+				Metadata: &chart.Metadata{
+					APIVersion: chart.APIVersionV3,
+					Name:       "ahab",
+					Version:    "1.2.3",
+				},
+				ModTime: modTime,
+				Lock: &chart.Lock{
+					Digest: "testdigest",
+				},
+				Files: []*common.File{
+					{Name: "scheherazade/shahryar.txt", ModTime: modTime, Data: []byte("1,001 Nights")},
+					{Name: "scheherazade/dunyazad.txt", ModTime: modTime, Data: []byte("1,001 Nights again")},
+				},
+				Schema:        []byte("{\n  \"title\": \"Values\"\n}"),
+				SchemaModTime: modTime,
+			},
+			want: "566bb87d0a044828e1e3acc4e9849b2c378eb9156a8662ceb618ea41b279bb10",
+		},
+	}
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			// create package
+			dest := path.Join(tmp, "newdir")
+			where, err := Save(test.chart, dest)
+			if err != nil {
+				t.Fatalf("Failed to save: %s", err)
+			}
+			// get shasum for package
+			result, err := sha256Sum(where)
+			if err != nil {
+				t.Fatalf("Failed to check shasum: %s", err)
+			}
+			// assert that the package SHA is what we wanted.
+			if result != test.want {
+				t.Errorf("FormatName() result = %v, want %v", result, test.want)
+			}
+		})
+	}
+}
+
+func sha256Sum(filePath string) (string, error) {
+	f, err := os.Open(filePath)
+	if err != nil {
+		return "", err
+	}
+	defer f.Close()
+
+	h := sha256.New()
+	if _, err := io.Copy(h, f); err != nil {
+		return "", err
+	}
+
+	return fmt.Sprintf("%x", h.Sum(nil)), nil
+}

pkg/action/action_test.go

@@ -122,9 +122,10 @@ type chartOptions struct {
 type chartOption func(*chartOptions)
 
 func buildChart(opts ...chartOption) *chart.Chart {
+	modTime := time.Now()
 	defaultTemplates := []*common.File{
-		{Name: "templates/hello", Data: []byte("hello: world")},
-		{Name: "templates/hooks", Data: []byte(manifestWithHook)},
+		{Name: "templates/hello", ModTime: modTime, Data: []byte("hello: world")},
+		{Name: "templates/hooks", ModTime: modTime, Data: []byte(manifestWithHook)},
 	}
 	return buildChartWithTemplates(defaultTemplates, opts...)
 }
@@ -180,8 +181,9 @@ func withValues(values map[string]interface{}) chartOption {
 func withNotes(notes string) chartOption {
 	return func(opts *chartOptions) {
 		opts.Templates = append(opts.Templates, &common.File{
-			Name: "templates/NOTES.txt",
-			Data: []byte(notes),
+			Name:    "templates/NOTES.txt",
+			ModTime: time.Now(),
+			Data:    []byte(notes),
 		})
 	}
 }
@@ -200,12 +202,13 @@ func withMetadataDependency(dependency chart.Dependency) chartOption {
 
 func withSampleTemplates() chartOption {
 	return func(opts *chartOptions) {
+		modTime := time.Now()
 		sampleTemplates := []*common.File{
 			// This adds basic templates and partials.
-			{Name: "templates/goodbye", Data: []byte("goodbye: world")},
-			{Name: "templates/empty", Data: []byte("")},
-			{Name: "templates/with-partials", Data: []byte(`hello: {{ template "_planet" . }}`)},
-			{Name: "templates/partials/_planet", Data: []byte(`{{define "_planet"}}Earth{{end}}`)},
+			{Name: "templates/goodbye", ModTime: modTime, Data: []byte("goodbye: world")},
+			{Name: "templates/empty", ModTime: modTime, Data: []byte("")},
+			{Name: "templates/with-partials", ModTime: modTime, Data: []byte(`hello: {{ template "_planet" . }}`)},
+			{Name: "templates/partials/_planet", ModTime: modTime, Data: []byte(`{{define "_planet"}}Earth{{end}}`)},
 		}
 		opts.Templates = append(opts.Templates, sampleTemplates...)
 	}
@@ -213,20 +216,21 @@ func withSampleTemplates() chartOption {
 
 func withSampleSecret() chartOption {
 	return func(opts *chartOptions) {
-		sampleSecret := &common.File{Name: "templates/secret.yaml", Data: []byte("apiVersion: v1\nkind: Secret\n")}
+		sampleSecret := &common.File{Name: "templates/secret.yaml", ModTime: time.Now(), Data: []byte("apiVersion: v1\nkind: Secret\n")}
 		opts.Templates = append(opts.Templates, sampleSecret)
 	}
 }
 
 func withSampleIncludingIncorrectTemplates() chartOption {
 	return func(opts *chartOptions) {
+		modTime := time.Now()
 		sampleTemplates := []*common.File{
 			// This adds basic templates and partials.
-			{Name: "templates/goodbye", Data: []byte("goodbye: world")},
-			{Name: "templates/empty", Data: []byte("")},
-			{Name: "templates/incorrect", Data: []byte("{{ .Values.bad.doh }}")},
-			{Name: "templates/with-partials", Data: []byte(`hello: {{ template "_planet" . }}`)},
-			{Name: "templates/partials/_planet", Data: []byte(`{{define "_planet"}}Earth{{end}}`)},
+			{Name: "templates/goodbye", ModTime: modTime, Data: []byte("goodbye: world")},
+			{Name: "templates/empty", ModTime: modTime, Data: []byte("")},
+			{Name: "templates/incorrect", ModTime: modTime, Data: []byte("{{ .Values.bad.doh }}")},
+			{Name: "templates/with-partials", ModTime: modTime, Data: []byte(`hello: {{ template "_planet" . }}`)},
+			{Name: "templates/partials/_planet", ModTime: modTime, Data: []byte(`{{define "_planet"}}Earth{{end}}`)},
 		}
 		opts.Templates = append(opts.Templates, sampleTemplates...)
 	}
@@ -235,7 +239,7 @@ func withSampleIncludingIncorrectTemplates() chartOption {
 func withMultipleManifestTemplate() chartOption {
 	return func(opts *chartOptions) {
 		sampleTemplates := []*common.File{
-			{Name: "templates/rbac", Data: []byte(rbacManifests)},
+			{Name: "templates/rbac", ModTime: time.Now(), Data: []byte(rbacManifests)},
 		}
 		opts.Templates = append(opts.Templates, sampleTemplates...)
 	}
@@ -852,7 +856,7 @@ func TestRenderResources_PostRenderer_MergeError(t *testing.T) {
 			Version:    "0.1.0",
 		},
 		Templates: []*common.File{
-			{Name: "templates/invalid", Data: []byte("invalid: yaml: content:")},
+			{Name: "templates/invalid", ModTime: time.Now(), Data: []byte("invalid: yaml: content:")},
 		},
 	}
 	values := map[string]interface{}{}

pkg/action/hooks_test.go

@@ -178,9 +178,10 @@ func runInstallForHooksWithSuccess(t *testing.T, manifest, expectedNamespace str
 	outBuffer := &bytes.Buffer{}
 	instAction.cfg.KubeClient = &kubefake.PrintingKubeClient{Out: io.Discard, LogOutput: outBuffer}
 
+	modTime := time.Now()
 	templates := []*common.File{
-		{Name: "templates/hello", Data: []byte("hello: world")},
-		{Name: "templates/hooks", Data: []byte(manifest)},
+		{Name: "templates/hello", ModTime: modTime, Data: []byte("hello: world")},
+		{Name: "templates/hooks", ModTime: modTime, Data: []byte(manifest)},
 	}
 	vals := map[string]interface{}{}
 
@@ -205,9 +206,10 @@ func runInstallForHooksWithFailure(t *testing.T, manifest, expectedNamespace str
 	outBuffer := &bytes.Buffer{}
 	failingClient.PrintingKubeClient = kubefake.PrintingKubeClient{Out: io.Discard, LogOutput: outBuffer}
 
+	modTime := time.Now()
 	templates := []*common.File{
-		{Name: "templates/hello", Data: []byte("hello: world")},
-		{Name: "templates/hooks", Data: []byte(manifest)},
+		{Name: "templates/hello", ModTime: modTime, Data: []byte("hello: world")},
+		{Name: "templates/hooks", ModTime: modTime, Data: []byte(manifest)},
 	}
 	vals := map[string]interface{}{}
 

pkg/action/install_test.go

@@ -427,8 +427,9 @@ func TestInstallRelease_DryRun_Lookup(t *testing.T) {
 
 	mockChart := buildChart(withSampleTemplates())
 	mockChart.Templates = append(mockChart.Templates, &common.File{
-		Name: "templates/lookup",
-		Data: []byte(`goodbye: {{ lookup "v1" "Namespace" "" "___" }}`),
+		Name:    "templates/lookup",
+		ModTime: time.Now(),
+		Data:    []byte(`goodbye: {{ lookup "v1" "Namespace" "" "___" }}`),
 	})
 
 	res, err := instAction.Run(mockChart, vals)

pkg/action/show_test.go

@@ -18,6 +18,7 @@ package action
 
 import (
 	"testing"
+	"time"
 
 	"helm.sh/helm/v4/pkg/chart/common"
 	chart "helm.sh/helm/v4/pkg/chart/v2"
@@ -26,17 +27,18 @@ import (
 func TestShow(t *testing.T) {
 	config := actionConfigFixture(t)
 	client := NewShow(ShowAll, config)
+	modTime := time.Now()
 	client.chart = &chart.Chart{
 		Metadata: &chart.Metadata{Name: "alpine"},
 		Files: []*common.File{
-			{Name: "README.md", Data: []byte("README\n")},
-			{Name: "crds/ignoreme.txt", Data: []byte("error")},
-			{Name: "crds/foo.yaml", Data: []byte("---\nfoo\n")},
-			{Name: "crds/bar.json", Data: []byte("---\nbar\n")},
-			{Name: "crds/baz.yaml", Data: []byte("baz\n")},
+			{Name: "README.md", ModTime: modTime, Data: []byte("README\n")},
+			{Name: "crds/ignoreme.txt", ModTime: modTime, Data: []byte("error")},
+			{Name: "crds/foo.yaml", ModTime: modTime, Data: []byte("---\nfoo\n")},
+			{Name: "crds/bar.json", ModTime: modTime, Data: []byte("---\nbar\n")},
+			{Name: "crds/baz.yaml", ModTime: modTime, Data: []byte("baz\n")},
 		},
 		Raw: []*common.File{
-			{Name: "values.yaml", Data: []byte("VALUES\n")},
+			{Name: "values.yaml", ModTime: modTime, Data: []byte("VALUES\n")},
 		},
 		Values: map[string]interface{}{},
 	}
@@ -104,13 +106,14 @@ func TestShowValuesByJsonPathFormat(t *testing.T) {
 func TestShowCRDs(t *testing.T) {
 	config := actionConfigFixture(t)
 	client := NewShow(ShowCRDs, config)
+	modTime := time.Now()
 	client.chart = &chart.Chart{
 		Metadata: &chart.Metadata{Name: "alpine"},
 		Files: []*common.File{
-			{Name: "crds/ignoreme.txt", Data: []byte("error")},
-			{Name: "crds/foo.yaml", Data: []byte("---\nfoo\n")},
-			{Name: "crds/bar.json", Data: []byte("---\nbar\n")},
-			{Name: "crds/baz.yaml", Data: []byte("baz\n")},
+			{Name: "crds/ignoreme.txt", ModTime: modTime, Data: []byte("error")},
+			{Name: "crds/foo.yaml", ModTime: modTime, Data: []byte("---\nfoo\n")},
+			{Name: "crds/bar.json", ModTime: modTime, Data: []byte("---\nbar\n")},
+			{Name: "crds/baz.yaml", ModTime: modTime, Data: []byte("baz\n")},
 		},
 	}
 
@@ -137,12 +140,13 @@ baz
 func TestShowNoReadme(t *testing.T) {
 	config := actionConfigFixture(t)
 	client := NewShow(ShowAll, config)
+	modTime := time.Now()
 	client.chart = &chart.Chart{
 		Metadata: &chart.Metadata{Name: "alpine"},
 		Files: []*common.File{
-			{Name: "crds/ignoreme.txt", Data: []byte("error")},
-			{Name: "crds/foo.yaml", Data: []byte("---\nfoo\n")},
-			{Name: "crds/bar.json", Data: []byte("---\nbar\n")},
+			{Name: "crds/ignoreme.txt", ModTime: modTime, Data: []byte("error")},
+			{Name: "crds/foo.yaml", ModTime: modTime, Data: []byte("---\nfoo\n")},
+			{Name: "crds/bar.json", ModTime: modTime, Data: []byte("---\nbar\n")},
 		},
 	}
 

pkg/chart/common/file.go

@@ -15,6 +15,8 @@ limitations under the License.
 
 package common
 
+import "time"
+
 // File represents a file as a name/value pair.
 //
 // By convention, name is a relative path within the scope of the chart's
@@ -24,4 +26,6 @@ type File struct {
 	Name string `json:"name"`
 	// Data is the template as byte data.
 	Data []byte `json:"data"`
+	// ModTime is the file's mod-time
+	ModTime time.Time `json:"modtime,omitzero"`
 }

pkg/chart/common/util/values_test.go

@@ -18,6 +18,7 @@ package util
 
 import (
 	"testing"
+	"time"
 
 	"helm.sh/helm/v4/pkg/chart/common"
 	chart "helm.sh/helm/v4/pkg/chart/v2"
@@ -46,7 +47,7 @@ func TestToRenderValues(t *testing.T) {
 		Templates: []*common.File{},
 		Values:    chartValues,
 		Files: []*common.File{
-			{Name: "scheherazade/shahryar.txt", Data: []byte("1,001 Nights")},
+			{Name: "scheherazade/shahryar.txt", ModTime: time.Now(), Data: []byte("1,001 Nights")},
 		},
 	}
 	c.AddDependency(&chart.Chart{

pkg/chart/loader/archive/archive.go

@@ -29,6 +29,7 @@ import (
 	"path"
 	"regexp"
 	"strings"
+	"time"
 )
 
 // MaxDecompressedChartSize is the maximum size of a chart archive that will be
@@ -46,8 +47,9 @@ var utf8bom = []byte{0xEF, 0xBB, 0xBF}
 
 // BufferedFile represents an archive file buffered for later processing.
 type BufferedFile struct {
-	Name string
-	Data []byte
+	Name    string
+	ModTime time.Time
+	Data    []byte
 }
 
 // LoadArchiveFiles reads in files out of an archive into memory. This function
@@ -148,7 +150,7 @@ func LoadArchiveFiles(in io.Reader) ([]*BufferedFile, error) {
 
 		data := bytes.TrimPrefix(b.Bytes(), utf8bom)
 
-		files = append(files, &BufferedFile{Name: n, Data: data})
+		files = append(files, &BufferedFile{Name: n, ModTime: hd.ModTime, Data: data})
 		b.Reset()
 	}
 

pkg/chart/v2/chart.go

@@ -19,6 +19,7 @@ import (
 	"path/filepath"
 	"regexp"
 	"strings"
+	"time"
 
 	"helm.sh/helm/v4/pkg/chart/common"
 )
@@ -50,9 +51,13 @@ type Chart struct {
 	Values map[string]interface{} `json:"values"`
 	// Schema is an optional JSON schema for imposing structure on Values
 	Schema []byte `json:"schema"`
+	// SchemaModTime the schema was last modified
+	SchemaModTime time.Time `json:"schemamodtime,omitempty"`
 	// Files are miscellaneous files in a chart archive,
 	// e.g. README, LICENSE, etc.
 	Files []*common.File `json:"files"`
+	// ModTime the chart metadata was last modified
+	ModTime time.Time `json:"modtime,omitzero"`
 
 	parent       *Chart
 	dependencies []*Chart

pkg/chart/v2/chart_test.go

@@ -18,6 +18,7 @@ package v2
 import (
 	"encoding/json"
 	"testing"
+	"time"
 
 	"github.com/stretchr/testify/assert"
 
@@ -25,27 +26,33 @@ import (
 )
 
 func TestCRDs(t *testing.T) {
+	modTime := time.Now()
 	chrt := Chart{
 		Files: []*common.File{
 			{
-				Name: "crds/foo.yaml",
-				Data: []byte("hello"),
+				Name:    "crds/foo.yaml",
+				ModTime: modTime,
+				Data:    []byte("hello"),
 			},
 			{
-				Name: "bar.yaml",
-				Data: []byte("hello"),
+				Name:    "bar.yaml",
+				ModTime: modTime,
+				Data:    []byte("hello"),
 			},
 			{
-				Name: "crds/foo/bar/baz.yaml",
-				Data: []byte("hello"),
+				Name:    "crds/foo/bar/baz.yaml",
+				ModTime: modTime,
+				Data:    []byte("hello"),
 			},
 			{
-				Name: "crdsfoo/bar/baz.yaml",
-				Data: []byte("hello"),
+				Name:    "crdsfoo/bar/baz.yaml",
+				ModTime: modTime,
+				Data:    []byte("hello"),
 			},
 			{
-				Name: "crds/README.md",
-				Data: []byte("# hello"),
+				Name:    "crds/README.md",
+				ModTime: modTime,
+				Data:    []byte("# hello"),
 			},
 		},
 	}
@@ -61,8 +68,9 @@ func TestSaveChartNoRawData(t *testing.T) {
 	chrt := Chart{
 		Raw: []*common.File{
 			{
-				Name: "fhqwhgads.yaml",
-				Data: []byte("Everybody to the Limit"),
+				Name:    "fhqwhgads.yaml",
+				ModTime: time.Now(),
+				Data:    []byte("Everybody to the Limit"),
 			},
 		},
 	}
@@ -163,27 +171,33 @@ func TestChartFullPath(t *testing.T) {
 }
 
 func TestCRDObjects(t *testing.T) {
+	modTime := time.Now()
 	chrt := Chart{
 		Files: []*common.File{
 			{
-				Name: "crds/foo.yaml",
-				Data: []byte("hello"),
+				Name:    "crds/foo.yaml",
+				ModTime: modTime,
+				Data:    []byte("hello"),
 			},
 			{
-				Name: "bar.yaml",
-				Data: []byte("hello"),
+				Name:    "bar.yaml",
+				ModTime: modTime,
+				Data:    []byte("hello"),
 			},
 			{
-				Name: "crds/foo/bar/baz.yaml",
-				Data: []byte("hello"),
+				Name:    "crds/foo/bar/baz.yaml",
+				ModTime: modTime,
+				Data:    []byte("hello"),
 			},
 			{
-				Name: "crdsfoo/bar/baz.yaml",
-				Data: []byte("hello"),
+				Name:    "crdsfoo/bar/baz.yaml",
+				ModTime: modTime,
+				Data:    []byte("hello"),
 			},
 			{
-				Name: "crds/README.md",
-				Data: []byte("# hello"),
+				Name:    "crds/README.md",
+				ModTime: modTime,
+				Data:    []byte("# hello"),
 			},
 		},
 	}
@@ -193,16 +207,18 @@ func TestCRDObjects(t *testing.T) {
 			Name:     "crds/foo.yaml",
 			Filename: "crds/foo.yaml",
 			File: &common.File{
-				Name: "crds/foo.yaml",
-				Data: []byte("hello"),
+				Name:    "crds/foo.yaml",
+				ModTime: modTime,
+				Data:    []byte("hello"),
 			},
 		},
 		{
 			Name:     "crds/foo/bar/baz.yaml",
 			Filename: "crds/foo/bar/baz.yaml",
 			File: &common.File{
-				Name: "crds/foo/bar/baz.yaml",
-				Data: []byte("hello"),
+				Name:    "crds/foo/bar/baz.yaml",
+				ModTime: modTime,
+				Data:    []byte("hello"),
 			},
 		},
 	}

pkg/chart/v2/lint/rules/template_test.go

@@ -22,6 +22,7 @@ import (
 	"path/filepath"
 	"strings"
 	"testing"
+	"time"
 
 	"helm.sh/helm/v4/pkg/chart/common"
 	chart "helm.sh/helm/v4/pkg/chart/v2"
@@ -183,6 +184,7 @@ func TestValidateMetadataName(t *testing.T) {
 }
 
 func TestDeprecatedAPIFails(t *testing.T) {
+	modTime := time.Now()
 	mychart := chart.Chart{
 		Metadata: &chart.Metadata{
 			APIVersion: "v2",
@@ -192,12 +194,14 @@ func TestDeprecatedAPIFails(t *testing.T) {
 		},
 		Templates: []*common.File{
 			{
-				Name: "templates/baddeployment.yaml",
-				Data: []byte("apiVersion: apps/v1beta1\nkind: Deployment\nmetadata:\n  name: baddep\nspec: {selector: {matchLabels: {foo: bar}}}"),
+				Name:    "templates/baddeployment.yaml",
+				ModTime: modTime,
+				Data:    []byte("apiVersion: apps/v1beta1\nkind: Deployment\nmetadata:\n  name: baddep\nspec: {selector: {matchLabels: {foo: bar}}}"),
 			},
 			{
-				Name: "templates/goodsecret.yaml",
-				Data: []byte("apiVersion: v1\nkind: Secret\nmetadata:\n  name: goodsecret"),
+				Name:    "templates/goodsecret.yaml",
+				ModTime: modTime,
+				Data:    []byte("apiVersion: v1\nkind: Secret\nmetadata:\n  name: goodsecret"),
 			},
 		},
 	}
@@ -252,8 +256,9 @@ func TestStrictTemplateParsingMapError(t *testing.T) {
 		},
 		Templates: []*common.File{
 			{
-				Name: "templates/configmap.yaml",
-				Data: []byte(manifest),
+				Name:    "templates/configmap.yaml",
+				ModTime: time.Now(),
+				Data:    []byte(manifest),
 			},
 		},
 	}
@@ -381,8 +386,9 @@ func TestEmptyWithCommentsManifests(t *testing.T) {
 		},
 		Templates: []*common.File{
 			{
-				Name: "templates/empty-with-comments.yaml",
-				Data: []byte("#@formatter:off\n"),
+				Name:    "templates/empty-with-comments.yaml",
+				ModTime: time.Now(),
+				Data:    []byte("#@formatter:off\n"),
 			},
 		},
 	}

pkg/chart/v2/loader/directory.go

@@ -111,7 +111,7 @@ func LoadDir(dir string) (*chart.Chart, error) {
 
 		data = bytes.TrimPrefix(data, utf8bom)
 
-		files = append(files, &archive.BufferedFile{Name: n, Data: data})
+		files = append(files, &archive.BufferedFile{Name: n, ModTime: fi.ModTime(), Data: data})
 		return nil
 	}
 	if err = sympath.Walk(topdir, walk); err != nil {

pkg/chart/v2/loader/load.go

@@ -76,7 +76,7 @@ func LoadFiles(files []*archive.BufferedFile) (*chart.Chart, error) {
 	// do not rely on assumed ordering of files in the chart and crash
 	// if Chart.yaml was not coming early enough to initialize metadata
 	for _, f := range files {
-		c.Raw = append(c.Raw, &common.File{Name: f.Name, Data: f.Data})
+		c.Raw = append(c.Raw, &common.File{Name: f.Name, ModTime: f.ModTime, Data: f.Data})
 		if f.Name == "Chart.yaml" {
 			if c.Metadata == nil {
 				c.Metadata = new(chart.Metadata)
@@ -90,6 +90,7 @@ func LoadFiles(files []*archive.BufferedFile) (*chart.Chart, error) {
 			if c.Metadata.APIVersion == "" {
 				c.Metadata.APIVersion = chart.APIVersionV1
 			}
+			c.ModTime = f.ModTime
 		}
 	}
 	for _, f := range files {
@@ -110,6 +111,7 @@ func LoadFiles(files []*archive.BufferedFile) (*chart.Chart, error) {
 			c.Values = values
 		case f.Name == "values.schema.json":
 			c.Schema = f.Data
+			c.SchemaModTime = f.ModTime
 
 		// Deprecated: requirements.yaml is deprecated use Chart.yaml.
 		// We will handle it for you because we are nice people
@@ -124,7 +126,7 @@ func LoadFiles(files []*archive.BufferedFile) (*chart.Chart, error) {
 				return c, fmt.Errorf("cannot load requirements.yaml: %w", err)
 			}
 			if c.Metadata.APIVersion == chart.APIVersionV1 {
-				c.Files = append(c.Files, &common.File{Name: f.Name, Data: f.Data})
+				c.Files = append(c.Files, &common.File{Name: f.Name, ModTime: f.ModTime, Data: f.Data})
 			}
 		// Deprecated: requirements.lock is deprecated use Chart.lock.
 		case f.Name == "requirements.lock":
@@ -139,22 +141,22 @@ func LoadFiles(files []*archive.BufferedFile) (*chart.Chart, error) {
 				log.Printf("Warning: Dependency locking is handled in Chart.lock since apiVersion \"v2\". We recommend migrating to Chart.lock.")
 			}
 			if c.Metadata.APIVersion == chart.APIVersionV1 {
-				c.Files = append(c.Files, &common.File{Name: f.Name, Data: f.Data})
+				c.Files = append(c.Files, &common.File{Name: f.Name, ModTime: f.ModTime, Data: f.Data})
 			}
 
 		case strings.HasPrefix(f.Name, "templates/"):
-			c.Templates = append(c.Templates, &common.File{Name: f.Name, Data: f.Data})
+			c.Templates = append(c.Templates, &common.File{Name: f.Name, ModTime: f.ModTime, Data: f.Data})
 		case strings.HasPrefix(f.Name, "charts/"):
 			if filepath.Ext(f.Name) == ".prov" {
-				c.Files = append(c.Files, &common.File{Name: f.Name, Data: f.Data})
+				c.Files = append(c.Files, &common.File{Name: f.Name, ModTime: f.ModTime, Data: f.Data})
 				continue
 			}
 
 			fname := strings.TrimPrefix(f.Name, "charts/")
 			cname := strings.SplitN(fname, "/", 2)[0]
-			subcharts[cname] = append(subcharts[cname], &archive.BufferedFile{Name: fname, Data: f.Data})
+			subcharts[cname] = append(subcharts[cname], &archive.BufferedFile{Name: fname, ModTime: f.ModTime, Data: f.Data})
 		default:
-			c.Files = append(c.Files, &common.File{Name: f.Name, Data: f.Data})
+			c.Files = append(c.Files, &common.File{Name: f.Name, ModTime: f.ModTime, Data: f.Data})
 		}
 	}
 

pkg/chart/v2/loader/load_test.go

@@ -219,8 +219,9 @@ func TestLoadFiles_BadCases(t *testing.T) {
 			name: "These files contain only requirements.lock",
 			bufferedFiles: []*archive.BufferedFile{
 				{
-					Name: "requirements.lock",
-					Data: []byte(""),
+					Name:    "requirements.lock",
+					ModTime: time.Now(),
+					Data:    []byte(""),
 				},
 			},
 			expectError: "validation: chart.metadata.apiVersion is required"},
@@ -236,9 +237,11 @@ func TestLoadFiles_BadCases(t *testing.T) {
 }
 
 func TestLoadFiles(t *testing.T) {
+	modTime := time.Now()
 	goodFiles := []*archive.BufferedFile{
 		{
-			Name: "Chart.yaml",
+			Name:    "Chart.yaml",
+			ModTime: modTime,
 			Data: []byte(`apiVersion: v1
 name: frobnitz
 description: This is a frobnitz.
@@ -259,20 +262,24 @@ icon: https://example.com/64x64.png
 `),
 		},
 		{
-			Name: "values.yaml",
-			Data: []byte("var: some values"),
+			Name:    "values.yaml",
+			ModTime: modTime,
+			Data:    []byte("var: some values"),
 		},
 		{
-			Name: "values.schema.json",
-			Data: []byte("type: Values"),
+			Name:    "values.schema.json",
+			ModTime: modTime,
+			Data:    []byte("type: Values"),
 		},
 		{
-			Name: "templates/deployment.yaml",
-			Data: []byte("some deployment"),
+			Name:    "templates/deployment.yaml",
+			ModTime: modTime,
+			Data:    []byte("some deployment"),
 		},
 		{
-			Name: "templates/service.yaml",
-			Data: []byte("some service"),
+			Name:    "templates/service.yaml",
+			ModTime: modTime,
+			Data:    []byte("some service"),
 		},
 	}
 
@@ -312,26 +319,32 @@ icon: https://example.com/64x64.png
 // Test the order of file loading. The Chart.yaml file needs to come first for
 // later comparison checks. See https://github.com/helm/helm/pull/8948
 func TestLoadFilesOrder(t *testing.T) {
+	modTime := time.Now()
 	goodFiles := []*archive.BufferedFile{
 		{
-			Name: "requirements.yaml",
-			Data: []byte("dependencies:"),
+			Name:    "requirements.yaml",
+			ModTime: modTime,
+			Data:    []byte("dependencies:"),
 		},
 		{
-			Name: "values.yaml",
-			Data: []byte("var: some values"),
+			Name:    "values.yaml",
+			ModTime: modTime,
+			Data:    []byte("var: some values"),
 		},
 
 		{
-			Name: "templates/deployment.yaml",
-			Data: []byte("some deployment"),
+			Name:    "templates/deployment.yaml",
+			ModTime: modTime,
+			Data:    []byte("some deployment"),
 		},
 		{
-			Name: "templates/service.yaml",
-			Data: []byte("some service"),
+			Name:    "templates/service.yaml",
+			ModTime: modTime,
+			Data:    []byte("some service"),
 		},
 		{
-			Name: "Chart.yaml",
+			Name:    "Chart.yaml",
+			ModTime: modTime,
 			Data: []byte(`apiVersion: v1
 name: frobnitz
 description: This is a frobnitz.

pkg/chart/v2/util/create.go

@@ -660,7 +660,7 @@ func CreateFrom(chartfile *chart.Metadata, dest, src string) error {
 
 	for _, template := range schart.Templates {
 		newData := transform(string(template.Data), schart.Name())
-		updatedTemplates = append(updatedTemplates, &common.File{Name: template.Name, Data: newData})
+		updatedTemplates = append(updatedTemplates, &common.File{Name: template.Name, ModTime: template.ModTime, Data: newData})
 	}
 
 	schart.Templates = updatedTemplates

pkg/chart/v2/util/save.go

@@ -175,7 +175,7 @@ func writeTarContents(out *tar.Writer, c *chart.Chart, prefix string) error {
 	if err != nil {
 		return err
 	}
-	if err := writeToTar(out, filepath.Join(base, ChartfileName), cdata); err != nil {
+	if err := writeToTar(out, filepath.Join(base, ChartfileName), cdata, c.ModTime); err != nil {
 		return err
 	}
 
@@ -187,7 +187,7 @@ func writeTarContents(out *tar.Writer, c *chart.Chart, prefix string) error {
 			if err != nil {
 				return err
 			}
-			if err := writeToTar(out, filepath.Join(base, "Chart.lock"), ldata); err != nil {
+			if err := writeToTar(out, filepath.Join(base, "Chart.lock"), ldata, c.Lock.Generated); err != nil {
 				return err
 			}
 		}
@@ -196,7 +196,7 @@ func writeTarContents(out *tar.Writer, c *chart.Chart, prefix string) error {
 	// Save values.yaml
 	for _, f := range c.Raw {
 		if f.Name == ValuesfileName {
-			if err := writeToTar(out, filepath.Join(base, ValuesfileName), f.Data); err != nil {
+			if err := writeToTar(out, filepath.Join(base, ValuesfileName), f.Data, f.ModTime); err != nil {
 				return err
 			}
 		}
@@ -207,7 +207,7 @@ func writeTarContents(out *tar.Writer, c *chart.Chart, prefix string) error {
 		if !json.Valid(c.Schema) {
 			return errors.New("invalid JSON in " + SchemafileName)
 		}
-		if err := writeToTar(out, filepath.Join(base, SchemafileName), c.Schema); err != nil {
+		if err := writeToTar(out, filepath.Join(base, SchemafileName), c.Schema, c.SchemaModTime); err != nil {
 			return err
 		}
 	}
@@ -215,7 +215,7 @@ func writeTarContents(out *tar.Writer, c *chart.Chart, prefix string) error {
 	// Save templates
 	for _, f := range c.Templates {
 		n := filepath.Join(base, f.Name)
-		if err := writeToTar(out, n, f.Data); err != nil {
+		if err := writeToTar(out, n, f.Data, f.ModTime); err != nil {
 			return err
 		}
 	}
@@ -223,7 +223,7 @@ func writeTarContents(out *tar.Writer, c *chart.Chart, prefix string) error {
 	// Save files
 	for _, f := range c.Files {
 		n := filepath.Join(base, f.Name)
-		if err := writeToTar(out, n, f.Data); err != nil {
+		if err := writeToTar(out, n, f.Data, f.ModTime); err != nil {
 			return err
 		}
 	}
@@ -238,13 +238,13 @@ func writeTarContents(out *tar.Writer, c *chart.Chart, prefix string) error {
 }
 
 // writeToTar writes a single file to a tar archive.
-func writeToTar(out *tar.Writer, name string, body []byte) error {
+func writeToTar(out *tar.Writer, name string, body []byte, modTime time.Time) error {
 	// TODO: Do we need to create dummy parent directory names if none exist?
 	h := &tar.Header{
 		Name:    filepath.ToSlash(name),
 		Mode:    0644,
 		Size:    int64(len(body)),
-		ModTime: time.Now(),
+		ModTime: modTime,
 	}
 	if err := out.WriteHeader(h); err != nil {
 		return err

pkg/chart/v2/util/save_test.go

@@ -20,6 +20,8 @@ import (
 	"archive/tar"
 	"bytes"
 	"compress/gzip"
+	"crypto/sha256"
+	"fmt"
 	"io"
 	"os"
 	"path"
@@ -49,7 +51,7 @@ func TestSave(t *testing.T) {
 					Digest: "testdigest",
 				},
 				Files: []*common.File{
-					{Name: "scheherazade/shahryar.txt", Data: []byte("1,001 Nights")},
+					{Name: "scheherazade/shahryar.txt", ModTime: time.Now(), Data: []byte("1,001 Nights")},
 				},
 				Schema: []byte("{\n  \"title\": \"Values\"\n}"),
 			}
@@ -118,7 +120,7 @@ func TestSave(t *testing.T) {
 			Digest: "testdigest",
 		},
 		Files: []*common.File{
-			{Name: "scheherazade/shahryar.txt", Data: []byte("1,001 Nights")},
+			{Name: "scheherazade/shahryar.txt", ModTime: time.Now(), Data: []byte("1,001 Nights")},
 		},
 	}
 	_, err := Save(c, tmp)
@@ -153,14 +155,16 @@ func TestSavePreservesTimestamps(t *testing.T) {
 			Name:       "ahab",
 			Version:    "1.2.3",
 		},
+		ModTime: initialCreateTime,
 		Values: map[string]interface{}{
 			"imageName": "testimage",
 			"imageId":   42,
 		},
 		Files: []*common.File{
-			{Name: "scheherazade/shahryar.txt", Data: []byte("1,001 Nights")},
+			{Name: "scheherazade/shahryar.txt", ModTime: initialCreateTime, Data: []byte("1,001 Nights")},
 		},
-		Schema: []byte("{\n  \"title\": \"Values\"\n}"),
+		Schema:        []byte("{\n  \"title\": \"Values\"\n}"),
+		SchemaModTime: initialCreateTime,
 	}
 
 	where, err := Save(c, tmp)
@@ -173,8 +177,9 @@ func TestSavePreservesTimestamps(t *testing.T) {
 		t.Fatalf("Failed to parse tar: %v", err)
 	}
 
+	roundedTime := initialCreateTime.Round(time.Second)
 	for _, header := range allHeaders {
-		if header.ModTime.Before(initialCreateTime) {
+		if !header.ModTime.Equal(roundedTime) {
 			t.Fatalf("File timestamp not preserved: %v", header.ModTime)
 		}
 	}
@@ -217,6 +222,7 @@ func retrieveAllHeadersFromTar(path string) ([]*tar.Header, error) {
 func TestSaveDir(t *testing.T) {
 	tmp := t.TempDir()
 
+	modTime := time.Now()
 	c := &chart.Chart{
 		Metadata: &chart.Metadata{
 			APIVersion: chart.APIVersionV1,
@@ -224,10 +230,10 @@ func TestSaveDir(t *testing.T) {
 			Version:    "1.2.3",
 		},
 		Files: []*common.File{
-			{Name: "scheherazade/shahryar.txt", Data: []byte("1,001 Nights")},
+			{Name: "scheherazade/shahryar.txt", ModTime: modTime, Data: []byte("1,001 Nights")},
 		},
 		Templates: []*common.File{
-			{Name: path.Join(TemplatesDir, "nested", "dir", "thing.yaml"), Data: []byte("abc: {{ .Values.abc }}")},
+			{Name: path.Join(TemplatesDir, "nested", "dir", "thing.yaml"), ModTime: modTime, Data: []byte("abc: {{ .Values.abc }}")},
 		},
 	}
 
@@ -263,3 +269,90 @@ func TestSaveDir(t *testing.T) {
 		t.Fatalf("Did not get expected error for chart named %q", c.Name())
 	}
 }
+
+func TestRepeatableSave(t *testing.T) {
+	tmp := t.TempDir()
+	defer os.RemoveAll(tmp)
+	modTime := time.Date(2021, 9, 1, 20, 34, 58, 651387237, time.UTC)
+	tests := []struct {
+		name  string
+		chart *chart.Chart
+		want  string
+	}{
+		{
+			name: "Package 1 file",
+			chart: &chart.Chart{
+				Metadata: &chart.Metadata{
+					APIVersion: chart.APIVersionV1,
+					Name:       "ahab",
+					Version:    "1.2.3",
+				},
+				ModTime: modTime,
+				Lock: &chart.Lock{
+					Digest: "testdigest",
+				},
+				Files: []*common.File{
+					{Name: "scheherazade/shahryar.txt", ModTime: modTime, Data: []byte("1,001 Nights")},
+				},
+				Schema:        []byte("{\n  \"title\": \"Values\"\n}"),
+				SchemaModTime: modTime,
+			},
+			want: "5e14a06037e5d4cb277c7b21770639d4e1a337be9ae391460e50653bac5a80ed",
+		},
+		{
+			name: "Package 2 files",
+			chart: &chart.Chart{
+				Metadata: &chart.Metadata{
+					APIVersion: chart.APIVersionV1,
+					Name:       "ahab",
+					Version:    "1.2.3",
+				},
+				ModTime: modTime,
+				Lock: &chart.Lock{
+					Digest: "testdigest",
+				},
+				Files: []*common.File{
+					{Name: "scheherazade/shahryar.txt", ModTime: modTime, Data: []byte("1,001 Nights")},
+					{Name: "scheherazade/dunyazad.txt", ModTime: modTime, Data: []byte("1,001 Nights again")},
+				},
+				Schema:        []byte("{\n  \"title\": \"Values\"\n}"),
+				SchemaModTime: modTime,
+			},
+			want: "6967787da46fbfcc563cad31240e564e14f2602e6f66302129a59a9669622a36",
+		},
+	}
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			// create package
+			dest := path.Join(tmp, "newdir")
+			where, err := Save(test.chart, dest)
+			if err != nil {
+				t.Fatalf("Failed to save: %s", err)
+			}
+			// get shasum for package
+			result, err := sha256Sum(where)
+			if err != nil {
+				t.Fatalf("Failed to check shasum: %s", err)
+			}
+			// assert that the package SHA is what we wanted.
+			if result != test.want {
+				t.Errorf("FormatName() result = %v, want %v", result, test.want)
+			}
+		})
+	}
+}
+
+func sha256Sum(filePath string) (string, error) {
+	f, err := os.Open(filePath)
+	if err != nil {
+		return "", err
+	}
+	defer f.Close()
+
+	h := sha256.New()
+	if _, err := io.Copy(h, f); err != nil {
+		return "", err
+	}
+
+	return fmt.Sprintf("%x", h.Sum(nil)), nil
+}

pkg/cmd/upgrade_test.go

@@ -23,6 +23,7 @@ import (
 	"reflect"
 	"strings"
 	"testing"
+	"time"
 
 	"helm.sh/helm/v4/pkg/chart/common"
 	chart "helm.sh/helm/v4/pkg/chart/v2"
@@ -383,7 +384,7 @@ func prepareMockRelease(t *testing.T, releaseName string) (func(n string, v int,
 			Description: "A Helm chart for Kubernetes",
 			Version:     "0.1.0",
 		},
-		Templates: []*common.File{{Name: "templates/configmap.yaml", Data: configmapData}},
+		Templates: []*common.File{{Name: "templates/configmap.yaml", ModTime: time.Now(), Data: configmapData}},
 	}
 	chartPath := filepath.Join(tmpChart, cfile.Metadata.Name)
 	if err := chartutil.SaveDir(cfile, tmpChart); err != nil {
@@ -484,6 +485,7 @@ func prepareMockReleaseWithSecret(t *testing.T, releaseName string) (func(n stri
 	if err != nil {
 		t.Fatalf("Error loading template yaml %v", err)
 	}
+	modTime := time.Now()
 	cfile := &chart.Chart{
 		Metadata: &chart.Metadata{
 			APIVersion:  chart.APIVersionV1,
@@ -491,7 +493,7 @@ func prepareMockReleaseWithSecret(t *testing.T, releaseName string) (func(n stri
 			Description: "A Helm chart for Kubernetes",
 			Version:     "0.1.0",
 		},
-		Templates: []*common.File{{Name: "templates/configmap.yaml", Data: configmapData}, {Name: "templates/secret.yaml", Data: secretData}},
+		Templates: []*common.File{{Name: "templates/configmap.yaml", ModTime: modTime, Data: configmapData}, {Name: "templates/secret.yaml", ModTime: modTime, Data: secretData}},
 	}
 	chartPath := filepath.Join(tmpChart, cfile.Metadata.Name)
 	if err := chartutil.SaveDir(cfile, tmpChart); err != nil {

pkg/engine/engine_test.go

@@ -23,6 +23,7 @@ import (
 	"sync"
 	"testing"
 	"text/template"
+	"time"
 
 	"github.com/stretchr/testify/assert"
 
@@ -90,17 +91,18 @@ func TestFuncMap(t *testing.T) {
 }
 
 func TestRender(t *testing.T) {
+	modTime := time.Now()
 	c := &chart.Chart{
 		Metadata: &chart.Metadata{
 			Name:    "moby",
 			Version: "1.2.3",
 		},
 		Templates: []*common.File{
-			{Name: "templates/test1", Data: []byte("{{.Values.outer | title }} {{.Values.inner | title}}")},
-			{Name: "templates/test2", Data: []byte("{{.Values.global.callme | lower }}")},
-			{Name: "templates/test3", Data: []byte("{{.noValue}}")},
-			{Name: "templates/test4", Data: []byte("{{toJson .Values}}")},
-			{Name: "templates/test5", Data: []byte("{{getHostByName \"helm.sh\"}}")},
+			{Name: "templates/test1", ModTime: modTime, Data: []byte("{{.Values.outer | title }} {{.Values.inner | title}}")},
+			{Name: "templates/test2", ModTime: modTime, Data: []byte("{{.Values.global.callme | lower }}")},
+			{Name: "templates/test3", ModTime: modTime, Data: []byte("{{.noValue}}")},
+			{Name: "templates/test4", ModTime: modTime, Data: []byte("{{toJson .Values}}")},
+			{Name: "templates/test5", ModTime: modTime, Data: []byte("{{getHostByName \"helm.sh\"}}")},
 		},
 		Values: map[string]interface{}{"outer": "DEFAULT", "inner": "DEFAULT"},
 	}
@@ -140,14 +142,16 @@ func TestRender(t *testing.T) {
 }
 
 func TestRenderRefsOrdering(t *testing.T) {
+	modTime := time.Now()
+
 	parentChart := &chart.Chart{
 		Metadata: &chart.Metadata{
 			Name:    "parent",
 			Version: "1.2.3",
 		},
 		Templates: []*common.File{
-			{Name: "templates/_helpers.tpl", Data: []byte(`{{- define "test" -}}parent value{{- end -}}`)},
-			{Name: "templates/test.yaml", Data: []byte(`{{ tpl "{{ include \"test\" . }}" . }}`)},
+			{Name: "templates/_helpers.tpl", ModTime: modTime, Data: []byte(`{{- define "test" -}}parent value{{- end -}}`)},
+			{Name: "templates/test.yaml", ModTime: modTime, Data: []byte(`{{ tpl "{{ include \"test\" . }}" . }}`)},
 		},
 	}
 	childChart := &chart.Chart{
@@ -156,7 +160,7 @@ func TestRenderRefsOrdering(t *testing.T) {
 			Version: "1.2.3",
 		},
 		Templates: []*common.File{
-			{Name: "templates/_helpers.tpl", Data: []byte(`{{- define "test" -}}child value{{- end -}}`)},
+			{Name: "templates/_helpers.tpl", ModTime: modTime, Data: []byte(`{{- define "test" -}}child value{{- end -}}`)},
 		},
 	}
 	parentChart.AddDependency(childChart)
@@ -220,7 +224,7 @@ func TestRenderWithDNS(t *testing.T) {
 			Version: "1.2.3",
 		},
 		Templates: []*common.File{
-			{Name: "templates/test1", Data: []byte("{{getHostByName \"helm.sh\"}}")},
+			{Name: "templates/test1", ModTime: time.Now(), Data: []byte("{{getHostByName \"helm.sh\"}}")},
 		},
 		Values: map[string]interface{}{},
 	}
@@ -355,10 +359,12 @@ func TestRenderWithClientProvider(t *testing.T) {
 		Values: map[string]interface{}{},
 	}
 
+	modTime := time.Now()
 	for name, exp := range cases {
 		c.Templates = append(c.Templates, &common.File{
-			Name: path.Join("templates", name),
-			Data: []byte(exp.template),
+			Name:    path.Join("templates", name),
+			ModTime: modTime,
+			Data:    []byte(exp.template),
 		})
 	}
 
@@ -393,7 +399,7 @@ func TestRenderWithClientProvider_error(t *testing.T) {
 			Version: "1.2.3",
 		},
 		Templates: []*common.File{
-			{Name: "templates/error", Data: []byte(`{{ lookup "v1" "Error" "" "" }}`)},
+			{Name: "templates/error", ModTime: time.Now(), Data: []byte(`{{ lookup "v1" "Error" "" "" }}`)},
 		},
 		Values: map[string]interface{}{},
 	}
@@ -558,18 +564,19 @@ func TestFailErrors(t *testing.T) {
 }
 
 func TestAllTemplates(t *testing.T) {
+	modTime := time.Now()
 	ch1 := &chart.Chart{
 		Metadata: &chart.Metadata{Name: "ch1"},
 		Templates: []*common.File{
-			{Name: "templates/foo", Data: []byte("foo")},
-			{Name: "templates/bar", Data: []byte("bar")},
+			{Name: "templates/foo", ModTime: modTime, Data: []byte("foo")},
+			{Name: "templates/bar", ModTime: modTime, Data: []byte("bar")},
 		},
 	}
 	dep1 := &chart.Chart{
 		Metadata: &chart.Metadata{Name: "laboratory mice"},
 		Templates: []*common.File{
-			{Name: "templates/pinky", Data: []byte("pinky")},
-			{Name: "templates/brain", Data: []byte("brain")},
+			{Name: "templates/pinky", ModTime: modTime, Data: []byte("pinky")},
+			{Name: "templates/brain", ModTime: modTime, Data: []byte("brain")},
 		},
 	}
 	ch1.AddDependency(dep1)
@@ -577,7 +584,7 @@ func TestAllTemplates(t *testing.T) {
 	dep2 := &chart.Chart{
 		Metadata: &chart.Metadata{Name: "same thing we do every night"},
 		Templates: []*common.File{
-			{Name: "templates/innermost", Data: []byte("innermost")},
+			{Name: "templates/innermost", ModTime: modTime, Data: []byte("innermost")},
 		},
 	}
 	dep1.AddDependency(dep2)
@@ -589,16 +596,17 @@ func TestAllTemplates(t *testing.T) {
 }
 
 func TestChartValuesContainsIsRoot(t *testing.T) {
+	modTime := time.Now()
 	ch1 := &chart.Chart{
 		Metadata: &chart.Metadata{Name: "parent"},
 		Templates: []*common.File{
-			{Name: "templates/isroot", Data: []byte("{{.Chart.IsRoot}}")},
+			{Name: "templates/isroot", ModTime: modTime, Data: []byte("{{.Chart.IsRoot}}")},
 		},
 	}
 	dep1 := &chart.Chart{
 		Metadata: &chart.Metadata{Name: "child"},
 		Templates: []*common.File{
-			{Name: "templates/isroot", Data: []byte("{{.Chart.IsRoot}}")},
+			{Name: "templates/isroot", ModTime: modTime, Data: []byte("{{.Chart.IsRoot}}")},
 		},
 	}
 	ch1.AddDependency(dep1)
@@ -621,16 +629,17 @@ func TestChartValuesContainsIsRoot(t *testing.T) {
 func TestRenderDependency(t *testing.T) {
 	deptpl := `{{define "myblock"}}World{{end}}`
 	toptpl := `Hello {{template "myblock"}}`
+	modTime := time.Now()
 	ch := &chart.Chart{
 		Metadata: &chart.Metadata{Name: "outerchart"},
 		Templates: []*common.File{
-			{Name: "templates/outer", Data: []byte(toptpl)},
+			{Name: "templates/outer", ModTime: modTime, Data: []byte(toptpl)},
 		},
 	}
 	ch.AddDependency(&chart.Chart{
 		Metadata: &chart.Metadata{Name: "innerchart"},
 		Templates: []*common.File{
-			{Name: "templates/inner", Data: []byte(deptpl)},
+			{Name: "templates/inner", ModTime: modTime, Data: []byte(deptpl)},
 		},
 	})
 
@@ -659,11 +668,12 @@ func TestRenderNestedValues(t *testing.T) {
 	// Ensure subcharts scopes are working.
 	subchartspath := "templates/subcharts.tpl"
 
+	modTime := time.Now()
 	deepest := &chart.Chart{
 		Metadata: &chart.Metadata{Name: "deepest"},
 		Templates: []*common.File{
-			{Name: deepestpath, Data: []byte(`And this same {{.Values.what}} that smiles {{.Values.global.when}}`)},
-			{Name: checkrelease, Data: []byte(`Tomorrow will be {{default "happy" .Release.Name }}`)},
+			{Name: deepestpath, ModTime: modTime, Data: []byte(`And this same {{.Values.what}} that smiles {{.Values.global.when}}`)},
+			{Name: checkrelease, ModTime: modTime, Data: []byte(`Tomorrow will be {{default "happy" .Release.Name }}`)},
 		},
 		Values: map[string]interface{}{"what": "milkshake", "where": "here"},
 	}
@@ -671,7 +681,7 @@ func TestRenderNestedValues(t *testing.T) {
 	inner := &chart.Chart{
 		Metadata: &chart.Metadata{Name: "herrick"},
 		Templates: []*common.File{
-			{Name: innerpath, Data: []byte(`Old {{.Values.who}} is still a-flyin'`)},
+			{Name: innerpath, ModTime: modTime, Data: []byte(`Old {{.Values.who}} is still a-flyin'`)},
 		},
 		Values: map[string]interface{}{"who": "Robert", "what": "glasses"},
 	}
@@ -680,8 +690,8 @@ func TestRenderNestedValues(t *testing.T) {
 	outer := &chart.Chart{
 		Metadata: &chart.Metadata{Name: "top"},
 		Templates: []*common.File{
-			{Name: outerpath, Data: []byte(`Gather ye {{.Values.what}} while ye may`)},
-			{Name: subchartspath, Data: []byte(`The glorious Lamp of {{.Subcharts.herrick.Subcharts.deepest.Values.where}}, the {{.Subcharts.herrick.Values.what}}`)},
+			{Name: outerpath, ModTime: modTime, Data: []byte(`Gather ye {{.Values.what}} while ye may`)},
+			{Name: subchartspath, ModTime: modTime, Data: []byte(`The glorious Lamp of {{.Subcharts.herrick.Subcharts.deepest.Values.where}}, the {{.Subcharts.herrick.Values.what}}`)},
 		},
 		Values: map[string]interface{}{
 			"what": "stinkweed",
@@ -754,23 +764,24 @@ func TestRenderNestedValues(t *testing.T) {
 }
 
 func TestRenderBuiltinValues(t *testing.T) {
+	modTime := time.Now()
 	inner := &chart.Chart{
 		Metadata: &chart.Metadata{Name: "Latium", APIVersion: chart.APIVersionV2},
 		Templates: []*common.File{
-			{Name: "templates/Lavinia", Data: []byte(`{{.Template.Name}}{{.Chart.Name}}{{.Release.Name}}`)},
-			{Name: "templates/From", Data: []byte(`{{.Files.author | printf "%s"}} {{.Files.Get "book/title.txt"}}`)},
+			{Name: "templates/Lavinia", ModTime: modTime, Data: []byte(`{{.Template.Name}}{{.Chart.Name}}{{.Release.Name}}`)},
+			{Name: "templates/From", ModTime: modTime, Data: []byte(`{{.Files.author | printf "%s"}} {{.Files.Get "book/title.txt"}}`)},
 		},
 		Files: []*common.File{
-			{Name: "author", Data: []byte("Virgil")},
-			{Name: "book/title.txt", Data: []byte("Aeneid")},
+			{Name: "author", ModTime: modTime, Data: []byte("Virgil")},
+			{Name: "book/title.txt", ModTime: modTime, Data: []byte("Aeneid")},
 		},
 	}
 
 	outer := &chart.Chart{
 		Metadata: &chart.Metadata{Name: "Troy", APIVersion: chart.APIVersionV2},
 		Templates: []*common.File{
-			{Name: "templates/Aeneas", Data: []byte(`{{.Template.Name}}{{.Chart.Name}}{{.Release.Name}}`)},
-			{Name: "templates/Amata", Data: []byte(`{{.Subcharts.Latium.Chart.Name}} {{.Subcharts.Latium.Files.author | printf "%s"}}`)},
+			{Name: "templates/Aeneas", ModTime: modTime, Data: []byte(`{{.Template.Name}}{{.Chart.Name}}{{.Release.Name}}`)},
+			{Name: "templates/Amata", ModTime: modTime, Data: []byte(`{{.Subcharts.Latium.Chart.Name}} {{.Subcharts.Latium.Files.author | printf "%s"}}`)},
 		},
 	}
 	outer.AddDependency(inner)
@@ -805,11 +816,12 @@ func TestRenderBuiltinValues(t *testing.T) {
 }
 
 func TestAlterFuncMap_include(t *testing.T) {
+	modTime := time.Now()
 	c := &chart.Chart{
 		Metadata: &chart.Metadata{Name: "conrad"},
 		Templates: []*common.File{
-			{Name: "templates/quote", Data: []byte(`{{include "conrad/templates/_partial" . | indent 2}} dead.`)},
-			{Name: "templates/_partial", Data: []byte(`{{.Release.Name}} - he`)},
+			{Name: "templates/quote", ModTime: modTime, Data: []byte(`{{include "conrad/templates/_partial" . | indent 2}} dead.`)},
+			{Name: "templates/_partial", ModTime: modTime, Data: []byte(`{{.Release.Name}} - he`)},
 		},
 	}
 
@@ -817,8 +829,8 @@ func TestAlterFuncMap_include(t *testing.T) {
 	d := &chart.Chart{
 		Metadata: &chart.Metadata{Name: "nested"},
 		Templates: []*common.File{
-			{Name: "templates/quote", Data: []byte(`{{include "nested/templates/quote" . | indent 2}} dead.`)},
-			{Name: "templates/_partial", Data: []byte(`{{.Release.Name}} - he`)},
+			{Name: "templates/quote", ModTime: modTime, Data: []byte(`{{include "nested/templates/quote" . | indent 2}} dead.`)},
+			{Name: "templates/_partial", ModTime: modTime, Data: []byte(`{{.Release.Name}} - he`)},
 		},
 	}
 
@@ -848,11 +860,12 @@ func TestAlterFuncMap_include(t *testing.T) {
 }
 
 func TestAlterFuncMap_require(t *testing.T) {
+	modTime := time.Now()
 	c := &chart.Chart{
 		Metadata: &chart.Metadata{Name: "conan"},
 		Templates: []*common.File{
-			{Name: "templates/quote", Data: []byte(`All your base are belong to {{ required "A valid 'who' is required" .Values.who }}`)},
-			{Name: "templates/bases", Data: []byte(`All {{ required "A valid 'bases' is required" .Values.bases }} of them!`)},
+			{Name: "templates/quote", ModTime: modTime, Data: []byte(`All your base are belong to {{ required "A valid 'who' is required" .Values.who }}`)},
+			{Name: "templates/bases", ModTime: modTime, Data: []byte(`All {{ required "A valid 'bases' is required" .Values.bases }} of them!`)},
 		},
 	}
 
@@ -913,7 +926,7 @@ func TestAlterFuncMap_tpl(t *testing.T) {
 	c := &chart.Chart{
 		Metadata: &chart.Metadata{Name: "TplFunction"},
 		Templates: []*common.File{
-			{Name: "templates/base", Data: []byte(`Evaluate tpl {{tpl "Value: {{ .Values.value}}" .}}`)},
+			{Name: "templates/base", ModTime: time.Now(), Data: []byte(`Evaluate tpl {{tpl "Value: {{ .Values.value}}" .}}`)},
 		},
 	}
 
@@ -942,7 +955,7 @@ func TestAlterFuncMap_tplfunc(t *testing.T) {
 	c := &chart.Chart{
 		Metadata: &chart.Metadata{Name: "TplFunction"},
 		Templates: []*common.File{
-			{Name: "templates/base", Data: []byte(`Evaluate tpl {{tpl "Value: {{ .Values.value | quote}}" .}}`)},
+			{Name: "templates/base", ModTime: time.Now(), Data: []byte(`Evaluate tpl {{tpl "Value: {{ .Values.value | quote}}" .}}`)},
 		},
 	}
 
@@ -968,11 +981,12 @@ func TestAlterFuncMap_tplfunc(t *testing.T) {
 }
 
 func TestAlterFuncMap_tplinclude(t *testing.T) {
+	modTime := time.Now()
 	c := &chart.Chart{
 		Metadata: &chart.Metadata{Name: "TplFunction"},
 		Templates: []*common.File{
-			{Name: "templates/base", Data: []byte(`{{ tpl "{{include ` + "`" + `TplFunction/templates/_partial` + "`" + ` .  | quote }}" .}}`)},
-			{Name: "templates/_partial", Data: []byte(`{{.Template.Name}}`)},
+			{Name: "templates/base", ModTime: modTime, Data: []byte(`{{ tpl "{{include ` + "`" + `TplFunction/templates/_partial` + "`" + ` .  | quote }}" .}}`)},
+			{Name: "templates/_partial", ModTime: modTime, Data: []byte(`{{.Template.Name}}`)},
 		},
 	}
 	v := common.Values{
@@ -998,12 +1012,14 @@ func TestAlterFuncMap_tplinclude(t *testing.T) {
 }
 
 func TestRenderRecursionLimit(t *testing.T) {
+	modTime := time.Now()
+
 	// endless recursion should produce an error
 	c := &chart.Chart{
 		Metadata: &chart.Metadata{Name: "bad"},
 		Templates: []*common.File{
-			{Name: "templates/base", Data: []byte(`{{include "recursion" . }}`)},
-			{Name: "templates/recursion", Data: []byte(`{{define "recursion"}}{{include "recursion" . }}{{end}}`)},
+			{Name: "templates/base", ModTime: modTime, Data: []byte(`{{include "recursion" . }}`)},
+			{Name: "templates/recursion", ModTime: modTime, Data: []byte(`{{define "recursion"}}{{include "recursion" . }}{{end}}`)},
 		},
 	}
 	v := common.Values{
@@ -1032,8 +1048,8 @@ func TestRenderRecursionLimit(t *testing.T) {
 	d := &chart.Chart{
 		Metadata: &chart.Metadata{Name: "overlook"},
 		Templates: []*common.File{
-			{Name: "templates/quote", Data: []byte(repeatedIncl.String())},
-			{Name: "templates/_function", Data: []byte(printFunc)},
+			{Name: "templates/quote", ModTime: modTime, Data: []byte(repeatedIncl.String())},
+			{Name: "templates/_function", ModTime: modTime, Data: []byte(printFunc)},
 		},
 	}
 
@@ -1053,15 +1069,16 @@ func TestRenderRecursionLimit(t *testing.T) {
 }
 
 func TestRenderLoadTemplateForTplFromFile(t *testing.T) {
+	modTime := time.Now()
 	c := &chart.Chart{
 		Metadata: &chart.Metadata{Name: "TplLoadFromFile"},
 		Templates: []*common.File{
-			{Name: "templates/base", Data: []byte(`{{ tpl (.Files.Get .Values.filename) . }}`)},
-			{Name: "templates/_function", Data: []byte(`{{define "test-function"}}test-function{{end}}`)},
+			{Name: "templates/base", ModTime: modTime, Data: []byte(`{{ tpl (.Files.Get .Values.filename) . }}`)},
+			{Name: "templates/_function", ModTime: modTime, Data: []byte(`{{define "test-function"}}test-function{{end}}`)},
 		},
 		Files: []*common.File{
-			{Name: "test", Data: []byte(`{{ tpl (.Files.Get .Values.filename2) .}}`)},
-			{Name: "test2", Data: []byte(`{{include "test-function" .}}{{define "nested-define"}}nested-define-content{{end}} {{include "nested-define" .}}`)},
+			{Name: "test", ModTime: modTime, Data: []byte(`{{ tpl (.Files.Get .Values.filename2) .}}`)},
+			{Name: "test2", ModTime: modTime, Data: []byte(`{{include "test-function" .}}{{define "nested-define"}}nested-define-content{{end}} {{include "nested-define" .}}`)},
 		},
 	}
 
@@ -1088,12 +1105,13 @@ func TestRenderLoadTemplateForTplFromFile(t *testing.T) {
 }
 
 func TestRenderTplEmpty(t *testing.T) {
+	modTime := time.Now()
 	c := &chart.Chart{
 		Metadata: &chart.Metadata{Name: "TplEmpty"},
 		Templates: []*common.File{
-			{Name: "templates/empty-string", Data: []byte(`{{tpl "" .}}`)},
-			{Name: "templates/empty-action", Data: []byte(`{{tpl "{{ \"\"}}" .}}`)},
-			{Name: "templates/only-defines", Data: []byte(`{{tpl "{{define \"not-invoked\"}}not-rendered{{end}}" .}}`)},
+			{Name: "templates/empty-string", ModTime: modTime, Data: []byte(`{{tpl "" .}}`)},
+			{Name: "templates/empty-action", ModTime: modTime, Data: []byte(`{{tpl "{{ \"\"}}" .}}`)},
+			{Name: "templates/only-defines", ModTime: modTime, Data: []byte(`{{tpl "{{define \"not-invoked\"}}not-rendered{{end}}" .}}`)},
 		},
 	}
 	v := common.Values{
@@ -1121,15 +1139,16 @@ func TestRenderTplEmpty(t *testing.T) {
 }
 
 func TestRenderTplTemplateNames(t *testing.T) {
+	modTime := time.Now()
 	// .Template.BasePath and .Name make it through
 	c := &chart.Chart{
 		Metadata: &chart.Metadata{Name: "TplTemplateNames"},
 		Templates: []*common.File{
-			{Name: "templates/default-basepath", Data: []byte(`{{tpl "{{ .Template.BasePath }}" .}}`)},
-			{Name: "templates/default-name", Data: []byte(`{{tpl "{{ .Template.Name }}" .}}`)},
-			{Name: "templates/modified-basepath", Data: []byte(`{{tpl "{{ .Template.BasePath }}" .Values.dot}}`)},
-			{Name: "templates/modified-name", Data: []byte(`{{tpl "{{ .Template.Name }}" .Values.dot}}`)},
-			{Name: "templates/modified-field", Data: []byte(`{{tpl "{{ .Template.Field }}" .Values.dot}}`)},
+			{Name: "templates/default-basepath", ModTime: modTime, Data: []byte(`{{tpl "{{ .Template.BasePath }}" .}}`)},
+			{Name: "templates/default-name", ModTime: modTime, Data: []byte(`{{tpl "{{ .Template.Name }}" .}}`)},
+			{Name: "templates/modified-basepath", ModTime: modTime, Data: []byte(`{{tpl "{{ .Template.BasePath }}" .Values.dot}}`)},
+			{Name: "templates/modified-name", ModTime: modTime, Data: []byte(`{{tpl "{{ .Template.Name }}" .Values.dot}}`)},
+			{Name: "templates/modified-field", ModTime: modTime, Data: []byte(`{{tpl "{{ .Template.Field }}" .Values.dot}}`)},
 		},
 	}
 	v := common.Values{
@@ -1168,12 +1187,13 @@ func TestRenderTplTemplateNames(t *testing.T) {
 }
 
 func TestRenderTplRedefines(t *testing.T) {
+	modTime := time.Now()
 	// Redefining a template inside 'tpl' does not affect the outer definition
 	c := &chart.Chart{
 		Metadata: &chart.Metadata{Name: "TplRedefines"},
 		Templates: []*common.File{
-			{Name: "templates/_partials", Data: []byte(`{{define "partial"}}original-in-partial{{end}}`)},
-			{Name: "templates/partial", Data: []byte(
+			{Name: "templates/_partials", ModTime: modTime, Data: []byte(`{{define "partial"}}original-in-partial{{end}}`)},
+			{Name: "templates/partial", ModTime: modTime, Data: []byte(
 				`before: {{include "partial" .}}\n{{tpl .Values.partialText .}}\nafter: {{include "partial" .}}`,
 			)},
 			{Name: "templates/manifest", Data: []byte(
@@ -1238,7 +1258,7 @@ func TestRenderTplMissingKey(t *testing.T) {
 	c := &chart.Chart{
 		Metadata: &chart.Metadata{Name: "TplMissingKey"},
 		Templates: []*common.File{
-			{Name: "templates/manifest", Data: []byte(
+			{Name: "templates/manifest", ModTime: time.Now(), Data: []byte(
 				`missingValue: {{tpl "{{.Values.noSuchKey}}" .}}`,
 			)},
 		},
@@ -1271,7 +1291,7 @@ func TestRenderTplMissingKeyString(t *testing.T) {
 	c := &chart.Chart{
 		Metadata: &chart.Metadata{Name: "TplMissingKeyStrict"},
 		Templates: []*common.File{
-			{Name: "templates/manifest", Data: []byte(
+			{Name: "templates/manifest", ModTime: time.Now(), Data: []byte(
 				`missingValue: {{tpl "{{.Values.noSuchKey}}" .}}`,
 			)},
 		},
@@ -1300,16 +1320,17 @@ func TestRenderTplMissingKeyString(t *testing.T) {
 }
 
 func TestNestedHelpersProducesMultilineStacktrace(t *testing.T) {
+	modTime := time.Now()
 	c := &chart.Chart{
 		Metadata: &chart.Metadata{Name: "NestedHelperFunctions"},
 		Templates: []*common.File{
-			{Name: "templates/svc.yaml", Data: []byte(
+			{Name: "templates/svc.yaml", ModTime: modTime, Data: []byte(
 				`name: {{ include "nested_helper.name" . }}`,
 			)},
-			{Name: "templates/_helpers_1.tpl", Data: []byte(
+			{Name: "templates/_helpers_1.tpl", ModTime: modTime, Data: []byte(
 				`{{- define "nested_helper.name" -}}{{- include "common.names.get_name" . -}}{{- end -}}`,
 			)},
-			{Name: "charts/common/templates/_helpers_2.tpl", Data: []byte(
+			{Name: "charts/common/templates/_helpers_2.tpl", ModTime: modTime, Data: []byte(
 				`{{- define "common.names.get_name" -}}{{- .Values.nonexistant.key | trunc 63 | trimSuffix "-" -}}{{- end -}}`,
 			)},
 		},
@@ -1338,16 +1359,17 @@ NestedHelperFunctions/charts/common/templates/_helpers_2.tpl:1:49
 }
 
 func TestMultilineNoTemplateAssociatedError(t *testing.T) {
+	modTime := time.Now()
 	c := &chart.Chart{
 		Metadata: &chart.Metadata{Name: "multiline"},
 		Templates: []*common.File{
-			{Name: "templates/svc.yaml", Data: []byte(
+			{Name: "templates/svc.yaml", ModTime: modTime, Data: []byte(
 				`name: {{ include "nested_helper.name" . }}`,
 			)},
-			{Name: "templates/test.yaml", Data: []byte(
+			{Name: "templates/test.yaml", ModTime: modTime, Data: []byte(
 				`{{ toYaml .Values }}`,
 			)},
-			{Name: "charts/common/templates/_helpers_2.tpl", Data: []byte(
+			{Name: "charts/common/templates/_helpers_2.tpl", ModTime: modTime, Data: []byte(
 				`{{ toYaml .Values }}`,
 			)},
 		},
@@ -1371,17 +1393,21 @@ template: no template "nested_helper.name" associated with template "gotpl"`
 }
 
 func TestRenderCustomTemplateFuncs(t *testing.T) {
+	modTime := time.Now()
+
 	// Create a chart with two templates that use custom functions
 	c := &chart.Chart{
 		Metadata: &chart.Metadata{Name: "CustomFunc"},
 		Templates: []*common.File{
 			{
-				Name: "templates/manifest",
-				Data: []byte(`{{exclaim .Values.message}}`),
+				Name:    "templates/manifest",
+				ModTime: modTime,
+				Data:    []byte(`{{exclaim .Values.message}}`),
 			},
 			{
-				Name: "templates/override",
-				Data: []byte(`{{ upper .Values.message }}`),
+				Name:    "templates/override",
+				ModTime: modTime,
+				Data:    []byte(`{{ upper .Values.message }}`),
 			},
 		},
 	}

pkg/release/v1/mock.go

@@ -100,7 +100,7 @@ func Mock(opts *MockReleaseOptions) *Release {
 				},
 			},
 			Templates: []*common.File{
-				{Name: "templates/foo.tpl", Data: []byte(MockManifest)},
+				{Name: "templates/foo.tpl", ModTime: time.Now(), Data: []byte(MockManifest)},
 			},
 		}
 	}