fix(helm-lint): do not validate metadata.name for List resources

Closes #13192

Signed-off-by: Thiago Perrotta <thiago@perrotta.dev>

pkg/lint/rules/template.go

@@ -160,7 +160,11 @@ func TemplatesWithSkipSchemaValidation(linter *support.Linter, values map[string
 				if yamlStruct != nil {
 					// NOTE: set to warnings to allow users to support out-of-date kubernetes
 					// Refs https://github.com/helm/helm/issues/8596
+					// Skip metadata name validation for List resources as they don't require meaningful names
+					// Refs https://github.com/helm/helm/issues/13192
+					if !isListResource(yamlStruct) {
 						linter.RunLinterRule(support.WarningSev, fpath, validateMetadataName(yamlStruct))
+					}
 					linter.RunLinterRule(support.WarningSev, fpath, validateNoDeprecations(yamlStruct, kubeVersion))
 
 					linter.RunLinterRule(support.ErrorSev, fpath, validateMatchSelector(yamlStruct, renderedContent))
@@ -235,6 +239,12 @@ func validateYamlContent(err error) error {
 	return nil
 }
 
+// isListResource returns true if the resource is a Kubernetes List type
+// (e.g. ConfigMapList, SecretList).
+func isListResource(obj *k8sYamlStruct) bool {
+	return strings.HasSuffix(obj.Kind, "List")
+}
+
 // validateMetadataName uses the correct validation function for the object
 // Kind, or if not set, defaults to the standard definition of a subdomain in
 // DNS (RFC 1123), used by most resources.

pkg/lint/rules/template_test.go

@@ -438,3 +438,48 @@ items:
 		t.Fatalf("List objects keep annotations should pass. got: %s", err)
 	}
 }
+
+func TestIsListResource(t *testing.T) {
+	tests := []struct {
+		kind     string
+		expected bool
+	}{
+		{"ConfigMap", false},
+		{"ConfigMapList", true},
+		{"Secret", false},
+		{"SecretList", true},
+		{"List", true},
+		{"", false},
+		{"SomethingListExtra", false},
+	}
+
+	for _, test := range tests {
+		t.Run(test.kind, func(t *testing.T) {
+			obj := &k8sYamlStruct{Kind: test.kind}
+			result := isListResource(obj)
+			if result != test.expected {
+				t.Errorf("isListResource(%q) = %v, expected %v", test.kind, result, test.expected)
+			}
+		})
+	}
+}
+
+func TestConfigMapListLinting(t *testing.T) {
+	linter := support.Linter{ChartDir: "./testdata/configmaplist-chart"}
+	Templates(&linter, values, namespace, strict)
+
+	// The ConfigMapList should not generate any lint warnings about metadata.name
+	for _, msg := range linter.Messages {
+		if strings.Contains(msg.Err.Error(), "object name does not conform to Kubernetes naming requirements") {
+			t.Errorf("ConfigMapList should not generate metadata name validation errors, but got: %v", msg.Err)
+		}
+	}
+
+	// Should have no errors or warnings
+	if len(linter.Messages) > 0 {
+		t.Errorf("Expected no lint messages for ConfigMapList, got %d messages:", len(linter.Messages))
+		for i, msg := range linter.Messages {
+			t.Logf("Message %d: %s", i, msg)
+		}
+	}
+}

pkg/lint/rules/testdata/configmaplist-chart/Chart.yaml

@@ -0,0 +1,6 @@
+apiVersion: v2
+name: configmaplist-chart
+description: Test chart with ConfigMapList
+type: application
+version: "0.1.0"
+appVersion: "1.0"

pkg/lint/rules/testdata/configmaplist-chart/templates/configmap.yaml

@@ -0,0 +1,7 @@
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: {{ .Release.Name }}-single-config
+  namespace: {{ .Release.Namespace }}
+data:
+  setting: "value"

pkg/lint/rules/testdata/configmaplist-chart/templates/configmaplist.yaml

@@ -0,0 +1,21 @@
+apiVersion: v1
+kind: ConfigMapList
+metadata:
+  # ConfigMapList objects don't require meaningful names
+  # This should not trigger lint warnings
+items:
+  - apiVersion: v1
+    kind: ConfigMap
+    metadata:
+      name: {{ .Release.Name }}-database-config
+      namespace: {{ .Release.Namespace }}
+    data:
+      host: {{ .Values.configs.database.host }}
+      port: "{{ .Values.configs.database.port }}"
+  - apiVersion: v1
+    kind: ConfigMap
+    metadata:
+      name: {{ .Release.Name }}-cache-config
+      namespace: {{ .Release.Namespace }}
+    data:
+      redis-url: {{ .Values.configs.cache.redis }}

pkg/lint/rules/testdata/configmaplist-chart/values.yaml

@@ -0,0 +1,7 @@
+# Default values for configmaplist-chart
+configs:
+  database:
+    host: localhost
+    port: 5432
+  cache:
+    redis: redis://localhost:6379