feat: add option to generate headless services

Add a new field `.spec.service.headless` which if set to true results in Flagger generating headless Services, i.e. with the Service's `.spec.clusterIP` set to None. Signed-off-by: Sanskar Jaiswal <[email protected]>
fluxcd · Jan 13, 2025 · e750a66 · e750a66
1 parent 16a6075
commit e750a66
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Showing 6 changed files with 21 additions and 0 deletions.
diff --git a/artifacts/flagger/crd.yaml b/artifacts/flagger/crd.yaml
@@ -198,6 +198,9 @@ spec:
                     portDiscovery:
                       description: Enable port dicovery
                       type: boolean
+                    headless:
+                      description: Headless if set to true, generates headless Kubernetes services.
+                      type: boolean
                     timeout:
                       description: HTTP or gRPC request timeout
                       type: string

diff --git a/charts/flagger/crds/crd.yaml b/charts/flagger/crds/crd.yaml
@@ -198,6 +198,9 @@ spec:
                     portDiscovery:
                       description: Enable port dicovery
                       type: boolean
+                    headless:
+                      description: Headless if set to true, generates headless Kubernetes services.
+                      type: boolean
                     timeout:
                       description: HTTP or gRPC request timeout
                       type: string

diff --git a/kustomize/base/flagger/crd.yaml b/kustomize/base/flagger/crd.yaml
@@ -198,6 +198,9 @@ spec:
                     portDiscovery:
                       description: Enable port dicovery
                       type: boolean
+                    headless:
+                      description: Headless if set to true, generates headless Kubernetes services.
+                      type: boolean
                     timeout:
                       description: HTTP or gRPC request timeout
                       type: string

diff --git a/pkg/apis/flagger/v1beta1/canary.go b/pkg/apis/flagger/v1beta1/canary.go
@@ -146,6 +146,11 @@ type CanaryService struct {
 	// PortDiscovery adds all container ports to the generated Kubernetes service
 	PortDiscovery bool `json:"portDiscovery"`
 
+	// Headless if set to true, generates headless Kubernetes services.
+	// ref: https://kubernetes.io/docs/concepts/services-networking/service/#headless-services
+	// +optional
+	Headless bool `json:"headless,omitempty"`
+
 	// Timeout of the HTTP or gRPC request
 	// +optional
 	Timeout string `json:"timeout,omitempty"`

diff --git a/pkg/router/kubernetes_default.go b/pkg/router/kubernetes_default.go
@@ -113,6 +113,9 @@ func (c *KubernetesDefaultRouter) reconcileService(canary *flaggerv1.Canary, nam
 			},
 		},
 	}
+	if canary.Spec.Service.Headless {
+		svcSpec.ClusterIP = "None"
+	}
 
 	if v := canary.Spec.Service.AppProtocol; v != "" {
 		svcSpec.Ports[0].AppProtocol = &v

diff --git a/pkg/router/kubernetes_default_test.go b/pkg/router/kubernetes_default_test.go
@@ -34,6 +34,8 @@ import (
 
 func TestServiceRouter_Create(t *testing.T) {
 	mocks := newFixture(nil)
+	mocks.canary.Spec.Service.Headless = true
+
 	router := &KubernetesDefaultRouter{
 		kubeClient:    mocks.kubeClient,
 		flaggerClient: mocks.flaggerClient,
@@ -53,11 +55,13 @@ func TestServiceRouter_Create(t *testing.T) {
 	assert.Equal(t, &appProtocol, canarySvc.Spec.Ports[0].AppProtocol)
 	assert.Equal(t, "http", canarySvc.Spec.Ports[0].Name)
 	assert.Equal(t, int32(9898), canarySvc.Spec.Ports[0].Port)
+	assert.Equal(t, "None", canarySvc.Spec.ClusterIP)
 
 	primarySvc, err := mocks.kubeClient.CoreV1().Services("default").Get(context.TODO(), "podinfo-primary", metav1.GetOptions{})
 	require.NoError(t, err)
 	assert.Equal(t, "http", primarySvc.Spec.Ports[0].Name)
 	assert.Equal(t, int32(9898), primarySvc.Spec.Ports[0].Port)
+	assert.Equal(t, "None", primarySvc.Spec.ClusterIP)
 }
 
 func TestServiceRouter_Update(t *testing.T) {