Fix incorrect timestamp when helm package

The files contained in the `tar` file from `helm package` did not have
the correct timestamp. This lack of timestamp occurred because we were
not writing any time to the tar header file.

pkg/chartutil/save.go

@@ -24,6 +24,7 @@ import (
 	"io/ioutil"
 	"os"
 	"path/filepath"
+	"time"
 
 	"github.com/ghodss/yaml"
 
@@ -208,6 +209,7 @@ func writeToTar(out *tar.Writer, name string, body []byte) error {
 		Name:    filepath.ToSlash(name),
 		Mode:    0755,
 		Size:    int64(len(body)),
+		ModTime: time.Now(),
 	}
 	if err := out.WriteHeader(h); err != nil {
 		return err

pkg/chartutil/save_test.go

@@ -17,10 +17,14 @@ limitations under the License.
 package chartutil
 
 import (
+	"archive/tar"
+	"compress/gzip"
+	"io"
 	"io/ioutil"
 	"os"
 	"strings"
 	"testing"
+	"time"
 
 	"github.com/golang/protobuf/ptypes/any"
 	"k8s.io/helm/pkg/proto/hapi/chart"
@@ -73,6 +77,82 @@ func TestSave(t *testing.T) {
 	}
 }
 
+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)
+
+	tmp, err := ioutil.TempDir("", "helm-")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(tmp)
+
+	c := &chart.Chart{
+		Metadata: &chart.Metadata{
+			Name:    "ahab",
+			Version: "1.2.3.4",
+		},
+		Values: &chart.Config{
+			Raw: "ship: Pequod",
+		},
+		Files: []*any.Any{
+			{TypeUrl: "scheherazade/shahryar.txt", Value: []byte("1,001 Nights")},
+		},
+	}
+
+	where, err := Save(c, tmp)
+	if err != nil {
+		t.Fatalf("Failed to save: %s", err)
+	}
+
+	allHeaders, err := retrieveAllHeadersFromTar(where)
+	if err != nil {
+		t.Fatalf("Failed to parse tar: %v", err)
+	}
+
+	for _, header := range allHeaders {
+		if header.ModTime.Before(initialCreateTime) {
+			t.Fatalf("File timestamp not preserved: %v", header.ModTime)
+		}
+	}
+}
+
+// We could refactor `load.go` to use this `retrieveAllHeadersFromTar` function
+// as well, so we are not duplicating components of the code which iterate
+// through the tar.
+func retrieveAllHeadersFromTar(path string) ([]*tar.Header, error) {
+	raw, err := os.Open(path)
+	if err != nil {
+		return nil, err
+	}
+	defer raw.Close()
+
+	unzipped, err := gzip.NewReader(raw)
+	if err != nil {
+		return nil, err
+	}
+	defer unzipped.Close()
+
+	tr := tar.NewReader(unzipped)
+	headers := []*tar.Header{}
+	for {
+		hd, err := tr.Next()
+		if err == io.EOF {
+			break
+		}
+
+		if err != nil {
+			return nil, err
+		}
+
+		headers = append(headers, hd)
+	}
+
+	return headers, nil
+}
+
 func TestSaveDir(t *testing.T) {
 	tmp, err := ioutil.TempDir("", "helm-")
 	if err != nil {