Add support for '.tar.gz' tarballs for helm charts

Signed-off-by: Kamalashree N <nagaraj.kamalashree@gmail.com>

pkg/action/lint.go

@@ -84,7 +84,7 @@ func lintChart(path string, vals map[string]interface{}, namespace string, stric
 	var chartPath string
 	linter := support.Linter{}
 
-	if strings.HasSuffix(path, ".tgz") {
+	if strings.HasSuffix(path, ".tgz") || strings.HasSuffix(path, ".tar.gz") {
 		tempDir, err := ioutil.TempDir("", "helm-lint")
 		if err != nil {
 			return linter, err

pkg/action/lint_test.go

@@ -26,6 +26,7 @@ var (
 	strict                       = false
 	archivedChartPath            = "../../cmd/helm/testdata/testcharts/compressedchart-0.1.0.tgz"
 	archivedChartPathWithHyphens = "../../cmd/helm/testdata/testcharts/compressedchart-with-hyphens-0.1.0.tgz"
+	archivedTarGzChartPath       = "../../cmd/helm/testdata/testcharts/compressedchart-0.1.0.tar.gz"
 	invalidArchivedChartPath     = "../../cmd/helm/testdata/testcharts/invalidcompressedchart0.1.0.tgz"
 	chartDirPath                 = "../../cmd/helm/testdata/testcharts/decompressedchart/"
 	chartMissingManifest         = "../../cmd/helm/testdata/testcharts/chart-missing-manifest"
@@ -42,6 +43,9 @@ func TestLintChart(t *testing.T) {
 	if _, err := lintChart(archivedChartPath, values, namespace, strict); err != nil {
 		t.Error(err)
 	}
+	if _, err := lintChart(archivedTarGzChartPath, values, namespace, strict); err != nil {
+		t.Error(err)
+	}
 	if _, err := lintChart(archivedChartPathWithHyphens, values, namespace, strict); err != nil {
 		t.Error(err)
 	}