Exclude label prefix propagation (#3607)

charts/gha-runner-scale-set-controller/templates/deployment.yaml

@@ -79,6 +79,9 @@ spec:
         - "--listener-metrics-endpoint="
         - "--metrics-addr=0"
         {{- end }}
+        {{- range .Values.flags.excludeLabelPropagationPrefixes }}
+        - "--exclude-label-propagation-prefix={{ . }}"
+        {{- end }}
         command:
         - "/manager"
         {{- with .Values.metrics }}

charts/gha-runner-scale-set-controller/tests/template_test.go

@@ -1035,3 +1035,41 @@ func TestControllerDeployment_MetricsPorts(t *testing.T) {
 		assert.Equal(t, value.frequency, 1, fmt.Sprintf("frequency of %q is not 1", key))
 	}
 }
+
+func TestDeployment_excludeLabelPropagationPrefixes(t *testing.T) {
+	t.Parallel()
+
+	// Path to the helm chart we will test
+	helmChartPath, err := filepath.Abs("../../gha-runner-scale-set-controller")
+	require.NoError(t, err)
+
+	chartContent, err := os.ReadFile(filepath.Join(helmChartPath, "Chart.yaml"))
+	require.NoError(t, err)
+
+	chart := new(Chart)
+	err = yaml.Unmarshal(chartContent, chart)
+	require.NoError(t, err)
+
+	releaseName := "test-arc"
+	namespaceName := "test-" + strings.ToLower(random.UniqueId())
+
+	options := &helm.Options{
+		Logger: logger.Discard,
+		SetValues: map[string]string{
+			"flags.excludeLabelPropagationPrefixes[0]": "prefix.com/",
+			"flags.excludeLabelPropagationPrefixes[1]": "complete.io/label",
+		},
+		KubectlOptions: k8s.NewKubectlOptions("", "", namespaceName),
+	}
+
+	output := helm.RenderTemplate(t, options, helmChartPath, releaseName, []string{"templates/deployment.yaml"})
+
+	var deployment appsv1.Deployment
+	helm.UnmarshalK8SYaml(t, output, &deployment)
+
+	require.Len(t, deployment.Spec.Template.Spec.Containers, 1, "Expected one container")
+	container := deployment.Spec.Template.Spec.Containers[0]
+
+	assert.Contains(t, container.Args, "--exclude-label-propagation-prefix=prefix.com/")
+	assert.Contains(t, container.Args, "--exclude-label-propagation-prefix=complete.io/label")
+}

charts/gha-runner-scale-set-controller/values.yaml

@@ -121,3 +121,12 @@ flags:
   ##   This can lead to a longer time to apply the change but it will ensure
   ##   that you don't have any overprovisioning of runners.
   updateStrategy: "immediate"
+
+  ## Defines a list of prefixes that should not be propagated to internal resources.
+  ## This is useful when you have labels that are used for internal purposes and should not be propagated to internal resources.
+  ## See https://github.com/actions/actions-runner-controller/issues/3533 for more information.
+  ##
+  ## By default, all labels are propagated to internal resources
+  ## Labels that match prefix specified in the list are excluded from propagation.
+  # excludeLabelPropagationPrefixes:
+  #   - "argocd.argoproj.io/instance"