Make the pod selector configurable

- default labels: app, name and app.kubernetes.io/name

cmd/flagger/main.go

@@ -18,6 +18,7 @@ import (
 	"k8s.io/client-go/tools/cache"
 	"k8s.io/client-go/tools/clientcmd"
 	"log"
+	"strings"
 	"time"
 )
 
@@ -36,6 +37,7 @@ var (
 	zapEncoding         string
 	namespace           string
 	meshProvider        string
+	selectorLabels      string
 )
 
 func init() {
@@ -53,6 +55,7 @@ func init() {
 	flag.StringVar(&zapEncoding, "zap-encoding", "json", "Zap logger encoding.")
 	flag.StringVar(&namespace, "namespace", "", "Namespace that flagger would watch canary object")
 	flag.StringVar(&meshProvider, "mesh-provider", "istio", "Service mesh provider, can be istio or appmesh")
+	flag.StringVar(&selectorLabels, "selector-labels", "app,name,app.kubernetes.io/name", "List of pod labels that Flagger uses to create pod selectors")
 }
 
 func main() {
@@ -101,6 +104,11 @@ func main() {
 		logger.Fatalf("Error calling Kubernetes API: %v", err)
 	}
 
+	labels := strings.Split(selectorLabels, ",")
+	if len(labels) < 1 {
+		logger.Fatalf("At least one selector label is required")
+	}
+
 	logger.Infof("Connected to Kubernetes API %s", ver)
 	if namespace != "" {
 		logger.Infof("Watching namespace %s", namespace)
@@ -137,6 +145,7 @@ func main() {
 		slack,
 		meshProvider,
 		version.VERSION,
+		labels,
 	)
 
 	flaggerInformerFactory.Start(stopCh)

pkg/canary/deployer.go

@@ -27,29 +27,31 @@ type Deployer struct {
 	FlaggerClient clientset.Interface
 	Logger        *zap.SugaredLogger
 	ConfigTracker ConfigTracker
+	Labels        []string
 }
 
-// Initialize creates the primary deployment and hpa
-// and scales to zero the canary deployment
-func (c *Deployer) Initialize(cd *flaggerv1.Canary) error {
+// Initialize creates the primary deployment, hpa,
+// scales to zero the canary deployment and returns the pod selector label
+func (c *Deployer) Initialize(cd *flaggerv1.Canary) (string, error) {
 	primaryName := fmt.Sprintf("%s-primary", cd.Spec.TargetRef.Name)
-	if err := c.createPrimaryDeployment(cd); err != nil {
-		return fmt.Errorf("creating deployment %s.%s failed: %v", primaryName, cd.Namespace, err)
+	label, err := c.createPrimaryDeployment(cd)
+	if err != nil {
+		return "", fmt.Errorf("creating deployment %s.%s failed: %v", primaryName, cd.Namespace, err)
 	}
 
 	if cd.Status.Phase == "" {
 		c.Logger.With("canary", fmt.Sprintf("%s.%s", cd.Name, cd.Namespace)).Infof("Scaling down %s.%s", cd.Spec.TargetRef.Name, cd.Namespace)
 		if err := c.Scale(cd, 0); err != nil {
-			return err
+			return "", err
 		}
 	}
 
 	if cd.Spec.AutoscalerRef != nil && cd.Spec.AutoscalerRef.Kind == "HorizontalPodAutoscaler" {
 		if err := c.createPrimaryHpa(cd); err != nil {
-			return fmt.Errorf("creating hpa %s.%s failed: %v", primaryName, cd.Namespace, err)
+			return "", fmt.Errorf("creating hpa %s.%s failed: %v", primaryName, cd.Namespace, err)
 		}
 	}
-	return nil
+	return label, nil
 }
 
 // Promote copies the pod spec, secrets and config maps from canary to primary
@@ -65,6 +67,12 @@ func (c *Deployer) Promote(cd *flaggerv1.Canary) error {
 		return fmt.Errorf("deployment %s.%s query error %v", targetName, cd.Namespace, err)
 	}
 
+	label, err := c.getSelectorLabel(canary)
+	if err != nil {
+		return fmt.Errorf("invalid label selector! Deployment %s.%s spec.selector.matchLabels must contain selector 'app: %s'",
+			targetName, cd.Namespace, targetName)
+	}
+
 	primary, err := c.KubeClient.AppsV1().Deployments(cd.Namespace).Get(primaryName, metav1.GetOptions{})
 	if err != nil {
 		if errors.IsNotFound(err) {
@@ -98,7 +106,7 @@ func (c *Deployer) Promote(cd *flaggerv1.Canary) error {
 	}
 	primaryCopy.Spec.Template.Annotations = annotations
 
-	primaryCopy.Spec.Template.Labels = makePrimaryLabels(canary.Spec.Template.Labels, primaryName)
+	primaryCopy.Spec.Template.Labels = makePrimaryLabels(canary.Spec.Template.Labels, primaryName, label)
 
 	_, err = c.KubeClient.AppsV1().Deployments(cd.Namespace).Update(primaryCopy)
 	if err != nil {
@@ -164,20 +172,21 @@ func (c *Deployer) Scale(cd *flaggerv1.Canary, replicas int32) error {
 	return nil
 }
 
-func (c *Deployer) createPrimaryDeployment(cd *flaggerv1.Canary) error {
+func (c *Deployer) createPrimaryDeployment(cd *flaggerv1.Canary) (string, error) {
 	targetName := cd.Spec.TargetRef.Name
 	primaryName := fmt.Sprintf("%s-primary", cd.Spec.TargetRef.Name)
 
 	canaryDep, err := c.KubeClient.AppsV1().Deployments(cd.Namespace).Get(targetName, metav1.GetOptions{})
 	if err != nil {
 		if errors.IsNotFound(err) {
-			return fmt.Errorf("deployment %s.%s not found, retrying", targetName, cd.Namespace)
+			return "", fmt.Errorf("deployment %s.%s not found, retrying", targetName, cd.Namespace)
 		}
-		return err
+		return "", err
 	}
 
-	if appSel, ok := canaryDep.Spec.Selector.MatchLabels["app"]; !ok || appSel != canaryDep.Name {
-		return fmt.Errorf("invalid label selector! Deployment %s.%s spec.selector.matchLabels must contain selector 'app: %s'",
+	label, err := c.getSelectorLabel(canaryDep)
+	if err != nil {
+		return "", fmt.Errorf("invalid label selector! Deployment %s.%s spec.selector.matchLabels must contain selector 'app: %s'",
 			targetName, cd.Namespace, targetName)
 	}
 
@@ -186,14 +195,14 @@ func (c *Deployer) createPrimaryDeployment(cd *flaggerv1.Canary) error {
 		// create primary secrets and config maps
 		configRefs, err := c.ConfigTracker.GetTargetConfigs(cd)
 		if err != nil {
-			return err
+			return "", err
 		}
 		if err := c.ConfigTracker.CreatePrimaryConfigs(cd, configRefs); err != nil {
-			return err
+			return "", err
 		}
 		annotations, err := c.makeAnnotations(canaryDep.Spec.Template.Annotations)
 		if err != nil {
-			return err
+			return "", err
 		}
 
 		replicas := int32(1)
@@ -223,12 +232,12 @@ func (c *Deployer) createPrimaryDeployment(cd *flaggerv1.Canary) error {
 				Strategy:                canaryDep.Spec.Strategy,
 				Selector: &metav1.LabelSelector{
 					MatchLabels: map[string]string{
-						"app": primaryName,
+						label: primaryName,
 					},
 				},
 				Template: corev1.PodTemplateSpec{
 					ObjectMeta: metav1.ObjectMeta{
-						Labels:      makePrimaryLabels(canaryDep.Spec.Template.Labels, primaryName),
+						Labels:      makePrimaryLabels(canaryDep.Spec.Template.Labels, primaryName, label),
 						Annotations: annotations,
 					},
 					// update spec with the primary secrets and config maps
@@ -239,13 +248,13 @@ func (c *Deployer) createPrimaryDeployment(cd *flaggerv1.Canary) error {
 
 		_, err = c.KubeClient.AppsV1().Deployments(cd.Namespace).Create(primaryDep)
 		if err != nil {
-			return err
+			return "", err
 		}
 
 		c.Logger.With("canary", fmt.Sprintf("%s.%s", cd.Name, cd.Namespace)).Infof("Deployment %s.%s created", primaryDep.GetName(), cd.Namespace)
 	}
 
-	return nil
+	return label, nil
 }
 
 func (c *Deployer) createPrimaryHpa(cd *flaggerv1.Canary) error {
@@ -320,15 +329,25 @@ func (c *Deployer) makeAnnotations(annotations map[string]string) (map[string]st
 	return res, nil
 }
 
-func makePrimaryLabels(labels map[string]string, primaryName string) map[string]string {
-	idKey := "app"
+// getSelectorLabel returns the selector match label
+func (c *Deployer) getSelectorLabel(deployment *appsv1.Deployment) (string, error) {
+	for _, l := range c.Labels {
+		if _, ok := deployment.Spec.Selector.MatchLabels[l]; ok {
+			return l, nil
+		}
+	}
+
+	return "", fmt.Errorf("selector not found")
+}
+
+func makePrimaryLabels(labels map[string]string, primaryName string, label string) map[string]string {
 	res := make(map[string]string)
 	for k, v := range labels {
-		if k != idKey {
+		if k != label {
 			res[k] = v
 		}
 	}
-	res[idKey] = primaryName
+	res[label] = primaryName
 
 	return res
 }

pkg/canary/deployer_test.go

@@ -9,7 +9,7 @@ import (
 
 func TestCanaryDeployer_Sync(t *testing.T) {
 	mocks := SetupMocks()
-	err := mocks.deployer.Initialize(mocks.canary)
+	_, err := mocks.deployer.Initialize(mocks.canary)
 	if err != nil {
 		t.Fatal(err.Error())
 	}
@@ -95,7 +95,7 @@ func TestCanaryDeployer_Sync(t *testing.T) {
 
 func TestCanaryDeployer_IsNewSpec(t *testing.T) {
 	mocks := SetupMocks()
-	err := mocks.deployer.Initialize(mocks.canary)
+	_, err := mocks.deployer.Initialize(mocks.canary)
 	if err != nil {
 		t.Fatal(err.Error())
 	}
@@ -118,7 +118,7 @@ func TestCanaryDeployer_IsNewSpec(t *testing.T) {
 
 func TestCanaryDeployer_Promote(t *testing.T) {
 	mocks := SetupMocks()
-	err := mocks.deployer.Initialize(mocks.canary)
+	_, err := mocks.deployer.Initialize(mocks.canary)
 	if err != nil {
 		t.Fatal(err.Error())
 	}
@@ -163,7 +163,7 @@ func TestCanaryDeployer_Promote(t *testing.T) {
 
 func TestCanaryDeployer_IsReady(t *testing.T) {
 	mocks := SetupMocks()
-	err := mocks.deployer.Initialize(mocks.canary)
+	_, err := mocks.deployer.Initialize(mocks.canary)
 	if err != nil {
 		t.Error("Expected primary readiness check to fail")
 	}
@@ -181,7 +181,7 @@ func TestCanaryDeployer_IsReady(t *testing.T) {
 
 func TestCanaryDeployer_SetFailedChecks(t *testing.T) {
 	mocks := SetupMocks()
-	err := mocks.deployer.Initialize(mocks.canary)
+	_, err := mocks.deployer.Initialize(mocks.canary)
 	if err != nil {
 		t.Fatal(err.Error())
 	}
@@ -203,7 +203,7 @@ func TestCanaryDeployer_SetFailedChecks(t *testing.T) {
 
 func TestCanaryDeployer_SetState(t *testing.T) {
 	mocks := SetupMocks()
-	err := mocks.deployer.Initialize(mocks.canary)
+	_, err := mocks.deployer.Initialize(mocks.canary)
 	if err != nil {
 		t.Fatal(err.Error())
 	}
@@ -225,7 +225,7 @@ func TestCanaryDeployer_SetState(t *testing.T) {
 
 func TestCanaryDeployer_SyncStatus(t *testing.T) {
 	mocks := SetupMocks()
-	err := mocks.deployer.Initialize(mocks.canary)
+	_, err := mocks.deployer.Initialize(mocks.canary)
 	if err != nil {
 		t.Fatal(err.Error())
 	}
@@ -264,7 +264,7 @@ func TestCanaryDeployer_SyncStatus(t *testing.T) {
 
 func TestCanaryDeployer_Scale(t *testing.T) {
 	mocks := SetupMocks()
-	err := mocks.deployer.Initialize(mocks.canary)
+	_, err := mocks.deployer.Initialize(mocks.canary)
 	if err != nil {
 		t.Fatal(err.Error())
 	}

pkg/canary/mock.go

@@ -46,6 +46,7 @@ func SetupMocks() Mocks {
 		FlaggerClient: flaggerClient,
 		KubeClient:    kubeClient,
 		Logger:        logger,
+		Labels:        []string{"app", "name"},
 		ConfigTracker: ConfigTracker{
 			Logger:        logger,
 			KubeClient:    kubeClient,
@@ -222,13 +223,13 @@ func newTestDeployment() *appsv1.Deployment {
 		Spec: appsv1.DeploymentSpec{
 			Selector: &metav1.LabelSelector{
 				MatchLabels: map[string]string{
-					"app": "podinfo",
+					"name": "podinfo",
 				},
 			},
 			Template: corev1.PodTemplateSpec{
 				ObjectMeta: metav1.ObjectMeta{
 					Labels: map[string]string{
-						"app": "podinfo",
+						"name": "podinfo",
 					},
 				},
 				Spec: corev1.PodSpec{
@@ -341,13 +342,13 @@ func newTestDeploymentV2() *appsv1.Deployment {
 		Spec: appsv1.DeploymentSpec{
 			Selector: &metav1.LabelSelector{
 				MatchLabels: map[string]string{
-					"app": "podinfo",
+					"name": "podinfo",
 				},
 			},
 			Template: corev1.PodTemplateSpec{
 				ObjectMeta: metav1.ObjectMeta{
 					Labels: map[string]string{
-						"app": "podinfo",
+						"name": "podinfo",
 					},
 				},
 				Spec: corev1.PodSpec{

pkg/controller/controller.go

@@ -60,6 +60,7 @@ func NewController(
 	notifier *notifier.Slack,
 	meshProvider string,
 	version string,
+	labels []string,
 ) *Controller {
 	logger.Debug("Creating event broadcaster")
 	flaggerscheme.AddToScheme(scheme.Scheme)
@@ -75,6 +76,7 @@ func NewController(
 		Logger:        logger,
 		KubeClient:    kubeClient,
 		FlaggerClient: flaggerClient,
+		Labels:        labels,
 		ConfigTracker: canary.ConfigTracker{
 			Logger:        logger,
 			KubeClient:    kubeClient,

pkg/controller/controller_test.go

@@ -69,6 +69,7 @@ func SetupMocks(abtest bool) Mocks {
 		Logger:        logger,
 		KubeClient:    kubeClient,
 		FlaggerClient: flaggerClient,
+		Labels:        []string{"app", "name"},
 		ConfigTracker: canary.ConfigTracker{
 			Logger:        logger,
 			KubeClient:    kubeClient,

pkg/controller/scheduler.go

@@ -90,7 +90,8 @@ func (c *Controller) advanceCanary(name string, namespace string, skipLivenessCh
 	primaryName := fmt.Sprintf("%s-primary", cd.Spec.TargetRef.Name)
 
 	// create primary deployment and hpa if needed
-	if err := c.deployer.Initialize(cd); err != nil {
+	label, err := c.deployer.Initialize(cd)
+	if err != nil {
 		c.recordEventWarningf(cd, "%v", err)
 		return
 	}
@@ -100,7 +101,7 @@ func (c *Controller) advanceCanary(name string, namespace string, skipLivenessCh
 	meshRouter := routerFactory.MeshRouter(c.meshProvider)
 
 	// create or update ClusterIP services
-	if err := routerFactory.KubernetesRouter().Reconcile(cd); err != nil {
+	if err := routerFactory.KubernetesRouter(label).Reconcile(cd); err != nil {
 		c.recordEventWarningf(cd, "%v", err)
 		return
 	}

pkg/router/factory.go

@@ -26,11 +26,12 @@ func NewFactory(kubeClient kubernetes.Interface,
 }
 
 // KubernetesRouter returns a ClusterIP service router
-func (factory *Factory) KubernetesRouter() *KubernetesRouter {
+func (factory *Factory) KubernetesRouter(label string) *KubernetesRouter {
 	return &KubernetesRouter{
 		logger:        factory.logger,
 		flaggerClient: factory.flaggerClient,
 		kubeClient:    factory.kubeClient,
+		label:         label,
 	}
 }
 

pkg/router/kubernetes.go

@@ -19,6 +19,7 @@ type KubernetesRouter struct {
 	kubeClient    kubernetes.Interface
 	flaggerClient clientset.Interface
 	logger        *zap.SugaredLogger
+	label         string
 }
 
 // Reconcile creates or updates the primary and canary services
@@ -64,7 +65,7 @@ func (c *KubernetesRouter) reconcileService(canary *flaggerv1.Canary, name strin
 
 	svcSpec := corev1.ServiceSpec{
 		Type:     corev1.ServiceTypeClusterIP,
-		Selector: map[string]string{"app": target},
+		Selector: map[string]string{c.label: target},
 		Ports: []corev1.ServicePort{
 			{
 				Name:     portName,