Update helm template -x to support children chart manifests in more cases

The previous code validated the manifests exist within the file system,
which only works when a chart is unpacked, meaning children charts
stored as tgz's in the parent chart's `charts/` directory don't exist as
individual files in the filesystem, causing validation to file.

Instead, we validate against the paths within the chart itself rather
than the filesystem, handling both chart.tgz's and charts that are
unpacked as directories in the chart/ directory.

cmd/helm/template.go

@@ -117,31 +117,10 @@ func (t *templateCmd) run(cmd *cobra.Command, args []string) error {
 	} else {
 		return err
 	}
-	// verify specified templates exist relative to chart
-	rf := []string{}
-	var af string
-	var err error
-	if len(t.renderFiles) > 0 {
-		for _, f := range t.renderFiles {
-			if !filepath.IsAbs(f) {
-				af, err = filepath.Abs(filepath.Join(t.chartPath, f))
-				if err != nil {
-					return fmt.Errorf("could not resolve template path: %s", err)
-				}
-			} else {
-				af = f
-			}
-			rf = append(rf, af)
-
-			if _, err := os.Stat(af); err != nil {
-				return fmt.Errorf("could not resolve template path: %s", err)
-			}
-		}
-	}
 
 	// verify that output-dir exists if provided
 	if t.outputDir != "" {
-		_, err = os.Stat(t.outputDir)
+		_, err := os.Stat(t.outputDir)
 		if os.IsNotExist(err) {
 			return fmt.Errorf("output-dir '%s' does not exist", t.outputDir)
 		}
@@ -232,19 +211,7 @@ func (t *templateCmd) run(cmd *cobra.Command, args []string) error {
 		m := tiller.Manifest{Name: k, Content: v, Head: &util.SimpleHead{Kind: h}}
 		listManifests = append(listManifests, m)
 	}
-	in := func(needle string, haystack []string) bool {
-		// make needle path absolute
-		d := strings.Split(needle, string(os.PathSeparator))
-		dd := d[1:]
-		an := filepath.Join(t.chartPath, strings.Join(dd, string(os.PathSeparator)))
 
-		for _, h := range haystack {
-			if h == an {
-				return true
-			}
-		}
-		return false
-	}
 	if settings.Debug {
 		rel := &release.Release{
 			Name:      t.releaseName,
@@ -257,10 +224,45 @@ func (t *templateCmd) run(cmd *cobra.Command, args []string) error {
 		printRelease(os.Stdout, rel)
 	}
 
-	for _, m := range tiller.SortByKind(listManifests) {
-		if len(t.renderFiles) > 0 && !in(m.Name, rf) {
-			continue
+	var manifestsToRender []tiller.Manifest
+
+	// if we have a list of files to render, then check that each of the
+	// provided files exists in the chart.
+	if len(t.renderFiles) > 0 {
+		for _, f := range t.renderFiles {
+			missing := true
+			if !filepath.IsAbs(f) {
+				newF, err := filepath.Abs(filepath.Join(t.chartPath, f))
+				if err != nil {
+					return fmt.Errorf("could not turn template path %s into absolute path: %s", f, err)
+				}
+				f = newF
 			}
+
+			for _, manifest := range listManifests {
+				manifestPathSplit := strings.Split(manifest.Name, string(filepath.Separator))
+				// remove the chart name from the path
+				manifestPathSplit = manifestPathSplit[1:]
+				toJoin := append([]string{t.chartPath}, manifestPathSplit...)
+				manifestPath := filepath.Join(toJoin...)
+
+				// if the filepath provided matches a manifest path in the
+				// chart, render that manifest
+				if f == manifestPath {
+					manifestsToRender = append(manifestsToRender, manifest)
+					missing = false
+				}
+			}
+			if missing {
+				return fmt.Errorf("could not find template %s in chart", f)
+			}
+		}
+	} else {
+		// no renderFiles provided, render all manifests in the chart
+		manifestsToRender = listManifests
+	}
+
+	for _, m := range tiller.SortByKind(manifestsToRender) {
 		data := m.Content
 		b := filepath.Base(m.Name)
 		if !t.showNotes && b == "NOTES.txt" {

cmd/helm/template_test.go

@@ -69,6 +69,13 @@ func TestTemplateCmd(t *testing.T) {
 			expectKey:   "subchart1/templates/service.yaml",
 			expectValue: "protocol: TCP\n    name: apache",
 		},
+		{
+			name:        "check_execute_subchart_template",
+			desc:        "verify --execute single template on a subchart template",
+			args:        []string{chartPath, "-x", "charts/subcharta/templates/service.yaml", "--set", "subcharta.service.name=foobar"},
+			expectKey:   "subchart1/charts/subcharta/templates/service.yaml",
+			expectValue: "protocol: TCP\n    name: foobar",
+		},
 		{
 			name:        "check_namespace",
 			desc:        "verify --namespace",