feat(helm): add linting support for '.tar.gz' tarballs for helm charts

When 'helm3 lint <chart-name>.tar.gz' is run, this will lint Chart.yaml in the package

Closes #6535

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

pkg/action/lint.go

@@ -77,7 +77,7 @@ 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, errors.Wrap(err, "unable to create temp dir to extract tarball")

pkg/action/lint_test.go

@@ -48,6 +48,10 @@ func TestLintChart(t *testing.T) {
 			name:      "archived-chart-path-with-hyphens",
 			chartPath: "../../cmd/helm/testdata/testcharts/compressedchart-with-hyphens-0.1.0.tgz",
 		},
+		{
+			name:      "archived-tar-gz-chart-path",
+			chartPath: "../../cmd/helm/testdata/testcharts/compressedchart-0.1.0.tar.gz",
+		},
 		{
 			name:      "invalid-archived-chart-path",
 			chartPath: "../../cmd/helm/testdata/testcharts/invalidcompressedchart0.1.0.tgz",