fix: #196 duplicate app.kubernetes.io/name in selectors and pod labels

pkg/processor/daemonset/daemonset.go

@@ -67,9 +67,12 @@ func (d daemonset) Process(appMeta helmify.AppMetadata, obj *unstructured.Unstru
 
 	name := appMeta.TrimName(obj.GetName())
 
-	matchLabels, err := yamlformat.Marshal(map[string]interface{}{"matchLabels": dae.Spec.Selector.MatchLabels}, 0)
-	if err != nil {
-		return true, nil, err
+	matchLabels := "matchLabels:"
+	if stripped := processor.StripSelectorLabels(dae.Spec.Selector.MatchLabels); len(stripped) > 0 {
+		matchLabels, err = yamlformat.Marshal(map[string]interface{}{"matchLabels": stripped}, 0)
+		if err != nil {
+			return true, nil, err
+		}
 	}
 	matchExpr := ""
 	if dae.Spec.Selector.MatchExpressions != nil {
@@ -82,11 +85,14 @@ func (d daemonset) Process(appMeta helmify.AppMetadata, obj *unstructured.Unstru
 	selector = strings.Trim(selector, " \n")
 	selector = string(yamlformat.Indent([]byte(selector), 4))
 
-	podLabels, err := yamlformat.Marshal(dae.Spec.Template.ObjectMeta.Labels, 8)
-	if err != nil {
-		return true, nil, err
+	podLabels := fmt.Sprintf("      {{- include \"%s.selectorLabels\" . | nindent 8 }}", appMeta.ChartName())
+	if strippedPodLabels := processor.StripSelectorLabels(dae.Spec.Template.ObjectMeta.Labels); len(strippedPodLabels) > 0 {
+		podLabels, err = yamlformat.Marshal(strippedPodLabels, 8)
+		if err != nil {
+			return true, nil, err
+		}
+		podLabels += fmt.Sprintf("\n      {{- include \"%s.selectorLabels\" . | nindent 8 }}", appMeta.ChartName())
 	}
-	podLabels += fmt.Sprintf("\n      {{- include \"%s.selectorLabels\" . | nindent 8 }}", appMeta.ChartName())
 
 	podAnnotations := ""
 	if len(dae.Spec.Template.ObjectMeta.Annotations) != 0 {

pkg/processor/deployment/deployment.go

@@ -93,9 +93,12 @@ func (d deployment) Process(appMeta helmify.AppMetadata, obj *unstructured.Unstr
 		return true, nil, err
 	}
 
-	matchLabels, err := yamlformat.Marshal(map[string]interface{}{"matchLabels": depl.Spec.Selector.MatchLabels}, 0)
-	if err != nil {
-		return true, nil, err
+	matchLabels := "matchLabels:"
+	if stripped := processor.StripSelectorLabels(depl.Spec.Selector.MatchLabels); len(stripped) > 0 {
+		matchLabels, err = yamlformat.Marshal(map[string]interface{}{"matchLabels": stripped}, 0)
+		if err != nil {
+			return true, nil, err
+		}
 	}
 	matchExpr := ""
 	if depl.Spec.Selector.MatchExpressions != nil {
@@ -108,11 +111,14 @@ func (d deployment) Process(appMeta helmify.AppMetadata, obj *unstructured.Unstr
 	selector = strings.Trim(selector, " \n")
 	selector = string(yamlformat.Indent([]byte(selector), 4))
 
-	podLabels, err := yamlformat.Marshal(depl.Spec.Template.ObjectMeta.Labels, 8)
-	if err != nil {
-		return true, nil, err
+	podLabels := fmt.Sprintf("      {{- include \"%s.selectorLabels\" . | nindent 8 }}", appMeta.ChartName())
+	if strippedPodLabels := processor.StripSelectorLabels(depl.Spec.Template.ObjectMeta.Labels); len(strippedPodLabels) > 0 {
+		podLabels, err = yamlformat.Marshal(strippedPodLabels, 8)
+		if err != nil {
+			return true, nil, err
+		}
+		podLabels += fmt.Sprintf("\n      {{- include \"%s.selectorLabels\" . | nindent 8 }}", appMeta.ChartName())
 	}
-	podLabels += fmt.Sprintf("\n      {{- include \"%s.selectorLabels\" . | nindent 8 }}", appMeta.ChartName())
 
 	podAnnotations := ""
 	if len(depl.Spec.Template.ObjectMeta.Annotations) != 0 {

pkg/processor/deployment/deployment_test.go

@@ -1,6 +1,7 @@
 package deployment
 
 import (
+	"bytes"
 	"testing"
 
 	"github.com/arttor/helmify/pkg/metadata"
@@ -24,10 +25,13 @@ spec:
     type: Recreate
   selector:
     matchLabels:
+      app.kubernetes.io/name: my-operator
       control-plane: controller-manager
   template:
     metadata:
       labels:
+        app.kubernetes.io/name: my-operator
+        app.kubernetes.io/instance: my-operator
         control-plane: controller-manager
     spec:
       containers:
@@ -125,9 +129,21 @@ func Test_deployment_Process(t *testing.T) {
 
 	t.Run("processed", func(t *testing.T) {
 		obj := internal.GenerateObj(strDepl)
-		processed, _, err := testInstance.Process(&metadata.Service{}, obj)
+		processed, tpl, err := testInstance.Process(&metadata.Service{}, obj)
 		assert.NoError(t, err)
 		assert.Equal(t, true, processed)
+
+		// issue #196: app.kubernetes.io/name and app.kubernetes.io/instance from
+		// selector.matchLabels and pod-template labels are provided by the
+		// chart.selectorLabels helper and must not be emitted hardcoded, otherwise
+		// the rendered manifest has duplicate YAML mapping keys.
+		var buf bytes.Buffer
+		assert.NoError(t, tpl.Write(&buf))
+		rendered := buf.String()
+		assert.Contains(t, rendered, "selectorLabels")
+		assert.Contains(t, rendered, "control-plane: controller-manager")
+		assert.NotContains(t, rendered, "app.kubernetes.io/name: my-operator")
+		assert.NotContains(t, rendered, "app.kubernetes.io/instance: my-operator")
 	})
 	t.Run("skipped", func(t *testing.T) {
 		obj := internal.TestNs

pkg/processor/meta.go

@@ -49,6 +49,32 @@ func WithAnnotations(values helmify.Values) MetaOpt {
 	}
 }
 
+// selectorLabelsKeys are the label keys emitted by the "<chart>.selectorLabels" helper.
+// They are stripped from selectors and pod-template labels so they are not rendered
+// twice (once hardcoded from the source manifest, once from the helper), which would
+// produce duplicate YAML mapping keys rejected by strict parsers (e.g. ArgoCD).
+var selectorLabelsKeys = map[string]struct{}{
+	"app.kubernetes.io/name":     {},
+	"app.kubernetes.io/instance": {},
+}
+
+// StripSelectorLabels returns a copy of labels with the keys provided by the
+// "<chart>.selectorLabels" helper removed. Use it on selectors and pod-template
+// labels before rendering them next to a selectorLabels include.
+func StripSelectorLabels(labels map[string]string) map[string]string {
+	if len(labels) == 0 {
+		return labels
+	}
+	stripped := make(map[string]string, len(labels))
+	for k, v := range labels {
+		if _, drop := selectorLabelsKeys[k]; drop {
+			continue
+		}
+		stripped[k] = v
+	}
+	return stripped
+}
+
 // ProcessObjMeta - returns object apiVersion, kind and metadata as helm template.
 func ProcessObjMeta(appMeta helmify.AppMetadata, obj *unstructured.Unstructured, opts ...MetaOpt) (string, error) {
 	options := &options{}

pkg/processor/meta_test.go

@@ -17,3 +17,54 @@ func TestProcessObjMeta(t *testing.T) {
 	assert.Contains(t, res, "chart-name.labels")
 	assert.Contains(t, res, "chart-name.fullname")
 }
+
+func TestStripSelectorLabels(t *testing.T) {
+	tests := []struct {
+		name   string
+		labels map[string]string
+		want   map[string]string
+	}{
+		{
+			name:   "nil labels returned as-is",
+			labels: nil,
+			want:   nil,
+		},
+		{
+			name:   "empty labels returned as-is",
+			labels: map[string]string{},
+			want:   map[string]string{},
+		},
+		{
+			name: "drops only keys provided by selectorLabels",
+			labels: map[string]string{
+				"app.kubernetes.io/name":     "myapp",
+				"app.kubernetes.io/instance": "myapp",
+				"app.kubernetes.io/version":  "1.0", // kept: not part of selectorLabels
+				"control-plane":              "controller-manager",
+			},
+			want: map[string]string{
+				"app.kubernetes.io/version": "1.0",
+				"control-plane":             "controller-manager",
+			},
+		},
+		{
+			name: "only selectorLabels keys yields empty map",
+			labels: map[string]string{
+				"app.kubernetes.io/name":     "myapp",
+				"app.kubernetes.io/instance": "myapp",
+			},
+			want: map[string]string{},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			input := tt.labels
+			got := StripSelectorLabels(input)
+			assert.Equal(t, tt.want, got)
+			// helper must not mutate the input map.
+			if len(input) > 0 {
+				assert.Contains(t, input, "app.kubernetes.io/name")
+			}
+		})
+	}
+}

pkg/processor/poddisruptionbudget/pdb.go

@@ -61,9 +61,20 @@ func (r pdb) Process(appMeta helmify.AppMetadata, obj *unstructured.Unstructured
 	name := appMeta.TrimName(obj.GetName())
 	nameCamel := strcase.ToLowerCamel(name)
 
-	selector, _ := yaml.Marshal(pdb.Spec.Selector)
-	selector = yamlformat.Indent(selector, 4)
-	selector = bytes.TrimRight(selector, "\n ")
+	var selector []byte
+	if pdb.Spec.Selector != nil {
+		sel := pdb.Spec.Selector.DeepCopy()
+		sel.MatchLabels = processor.StripSelectorLabels(sel.MatchLabels)
+		if len(sel.MatchLabels) == 0 && len(sel.MatchExpressions) == 0 {
+			// selector only had keys provided by selectorLabels; keep the matchLabels
+			// key so the include nests correctly under it (avoids an empty "{}").
+			selector = []byte("    matchLabels:")
+		} else {
+			raw, _ := yaml.Marshal(sel)
+			selector = yamlformat.Indent(raw, 4)
+			selector = bytes.TrimRight(selector, "\n ")
+		}
+	}
 
 	if spec.MaxUnavailable != nil {
 		_, err := values.Add(spec.MaxUnavailable.IntValue(), nameCamel, "maxUnavailable")

pkg/processor/service/service.go

@@ -80,9 +80,12 @@ func (r svc) Process(appMeta helmify.AppMetadata, obj *unstructured.Unstructured
 	shortName := strings.TrimPrefix(name, "controller-manager-")
 	shortNameCamel := strcase.ToLowerCamel(shortName)
 
-	selector, _ := yaml.Marshal(service.Spec.Selector)
-	selector = yamlformat.Indent(selector, 4)
-	selector = bytes.TrimRight(selector, "\n ")
+	var selector []byte
+	if stripped := processor.StripSelectorLabels(service.Spec.Selector); len(stripped) > 0 {
+		selector, _ = yaml.Marshal(stripped)
+		selector = yamlformat.Indent(selector, 4)
+		selector = bytes.TrimRight(selector, "\n ")
+	}
 
 	values := helmify.Values{}
 	svcType := service.Spec.Type

test_data/sample-app.yaml

@@ -11,10 +11,12 @@ spec:
   selector:
     matchLabels:
       app: myapp
+      app.kubernetes.io/name: myapp
   template:
     metadata:
       labels:
         app: myapp
+        app.kubernetes.io/name: myapp
     spec:
       initContainers:
         - name: init-container
@@ -145,6 +147,7 @@ spec:
       targetPort: https
   selector:
     app: myapp
+    app.kubernetes.io/name: myapp
 ---
 apiVersion: v1
 kind: Service
@@ -274,10 +277,12 @@ spec:
   selector:
     matchLabels:
       name: fluentd-elasticsearch
+      app.kubernetes.io/name: fluentd-elasticsearch
   template:
     metadata:
       labels:
         name: fluentd-elasticsearch
+        app.kubernetes.io/name: fluentd-elasticsearch
     spec:
       priorityClassName: system-node-critical
       tolerations:
@@ -404,3 +409,4 @@ spec:
   selector:
     matchLabels:
       app: nginx
+      app.kubernetes.io/name: nginx