Set proper IP family policy on NGINX LB Service

Problem: When provisioning the NGINX LoadBalancer Service, the IPFamily that's set in the NginxProxy resource (default dual) was not honored.

Solution: By default, set the IPFamily to PreferDualStack. If a user has specified otherwise in the NginxProxy resource, then set to SingleStack. The IPFamilies list is populated automatically by k8s based on the policy.

Author: sjberman

internal/controller/provisioner/objects.go

@@ -463,9 +463,12 @@ func buildNginxService(
 			Ports:                 servicePorts,
 			ExternalTrafficPolicy: servicePolicy,
 			Selector:              selectorLabels,
+			IPFamilyPolicy:        helpers.GetPointer(corev1.IPFamilyPolicyPreferDualStack),
 		},
 	}
 
+	setIPFamily(nProxyCfg, svc)
+
 	if serviceCfg.LoadBalancerIP != nil {
 		svc.Spec.LoadBalancerIP = *serviceCfg.LoadBalancerIP
 	}
@@ -479,6 +482,17 @@ func buildNginxService(
 	return svc
 }
 
+func setIPFamily(nProxyCfg *graph.EffectiveNginxProxy, svc *corev1.Service) {
+	if nProxyCfg != nil && nProxyCfg.IPFamily != nil && *nProxyCfg.IPFamily != ngfAPIv1alpha2.Dual {
+		svc.Spec.IPFamilyPolicy = helpers.GetPointer(corev1.IPFamilyPolicySingleStack)
+		if *nProxyCfg.IPFamily == ngfAPIv1alpha2.IPv4 {
+			svc.Spec.IPFamilies = []corev1.IPFamily{corev1.IPv4Protocol}
+		} else {
+			svc.Spec.IPFamilies = []corev1.IPFamily{corev1.IPv6Protocol}
+		}
+	}
+}
+
 func (p *NginxProvisioner) buildNginxDeployment(
 	objectMeta metav1.ObjectMeta,
 	nProxyCfg *graph.EffectiveNginxProxy,

internal/controller/provisioner/objects_test.go

@@ -161,6 +161,7 @@ func TestBuildNginxResourceObjects(t *testing.T) {
 	validateMeta(svc)
 	g.Expect(svc.Spec.Type).To(Equal(defaultServiceType))
 	g.Expect(svc.Spec.ExternalTrafficPolicy).To(Equal(defaultServicePolicy))
+	g.Expect(*svc.Spec.IPFamilyPolicy).To(Equal(corev1.IPFamilyPolicyPreferDualStack))
 
 	// service ports is sorted in ascending order by port number when we make the nginx object
 	g.Expect(svc.Spec.Ports).To(Equal([]corev1.ServicePort{
@@ -260,6 +261,7 @@ func TestBuildNginxResourceObjects_NginxProxyConfig(t *testing.T) {
 
 	resourceName := "gw-nginx"
 	nProxyCfg := &graph.EffectiveNginxProxy{
+		IPFamily: helpers.GetPointer(ngfAPIv1alpha2.IPv4),
 		Logging: &ngfAPIv1alpha2.NginxLogging{
 			ErrorLevel: helpers.GetPointer(ngfAPIv1alpha2.NginxLogLevelDebug),
 			AgentLevel: helpers.GetPointer(ngfAPIv1alpha2.AgentLogLevelDebug),
@@ -321,6 +323,8 @@ func TestBuildNginxResourceObjects_NginxProxyConfig(t *testing.T) {
 	g.Expect(svc.Spec.LoadBalancerIP).To(Equal("1.2.3.4"))
 	g.Expect(*svc.Spec.LoadBalancerClass).To(Equal("myLoadBalancerClass"))
 	g.Expect(svc.Spec.LoadBalancerSourceRanges).To(Equal([]string{"5.6.7.8"}))
+	g.Expect(*svc.Spec.IPFamilyPolicy).To(Equal(corev1.IPFamilyPolicySingleStack))
+	g.Expect(svc.Spec.IPFamilies).To(Equal([]corev1.IPFamily{corev1.IPv4Protocol}))
 
 	depObj := objects[5]
 	dep, ok := depObj.(*appsv1.Deployment)