Generate reproducible tarball

Signed-off-by: Tamal Saha <tamal@appscode.com>

pkg/chartutil/save.go

@@ -23,7 +23,7 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
-	"time"
+	"sort"
 
 	"github.com/pkg/errors"
 	"sigs.k8s.io/yaml"
@@ -203,6 +203,9 @@ func writeTarContents(out *tar.Writer, c *chart.Chart, prefix string) error {
 	}
 
 	// Save templates
+	sort.Slice(c.Templates, func(i, j int) bool {
+		return c.Templates[i].Name < c.Templates[j].Name
+	})
 	for _, f := range c.Templates {
 		n := filepath.Join(base, f.Name)
 		if err := writeToTar(out, n, f.Data); err != nil {
@@ -211,6 +214,9 @@ func writeTarContents(out *tar.Writer, c *chart.Chart, prefix string) error {
 	}
 
 	// Save files
+	sort.Slice(c.Files, func(i, j int) bool {
+		return c.Files[i].Name < c.Files[j].Name
+	})
 	for _, f := range c.Files {
 		n := filepath.Join(base, f.Name)
 		if err := writeToTar(out, n, f.Data); err != nil {
@@ -231,10 +237,9 @@ func writeTarContents(out *tar.Writer, c *chart.Chart, prefix string) error {
 func writeToTar(out *tar.Writer, name string, body []byte) 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(),
+		Name: filepath.ToSlash(name),
+		Mode: 0644,
+		Size: int64(len(body)),
 	}
 	if err := out.WriteHeader(h); err != nil {
 		return err

pkg/chartutil/save_test.go

@@ -123,12 +123,7 @@ func Indent(n int, text string) string {
 	return startOfLine.ReplaceAllLiteralString(text, indentation)
 }
 
-func TestSavePreservesTimestamps(t *testing.T) {
-	// Test executes so quickly that if we don't subtract a second, the
-	// check will fail because `initialCreateTime` will be identical to the
-	// written timestamp for the files.
-	initialCreateTime := time.Now().Add(-1 * time.Second)
-
+func TestSaveZerosOutTimestamps(t *testing.T) {
 	tmp, err := ioutil.TempDir("", "helm-")
 	if err != nil {
 		t.Fatal(err)
@@ -162,8 +157,8 @@ func TestSavePreservesTimestamps(t *testing.T) {
 	}
 
 	for _, header := range allHeaders {
-		if header.ModTime.Before(initialCreateTime) {
-			t.Fatalf("File timestamp not preserved: %v", header.ModTime)
+		if header.ModTime != time.Unix(0, 0) {
+			t.Fatalf("File %s timestamp is not zero", header.Name)
 		}
 	}
 }