fix: explicitly set ip family and family policy in gateway spec

internal/infrastructure/kubernetes/proxy/resource_provider.go

@@ -169,6 +169,20 @@ func (r *ResourceRender) Service() (*corev1.Service, error) {
 		serviceSpec.ExternalIPs = r.infra.Addresses
 	}
 
+	// Set IP family policy and families based on proxy config request
+	ipFamily := r.infra.GetProxyConfig().Spec.IPFamily
+	if ipFamily != nil {
+		// SingleStack+IPv4 is default behavior from K8s and so is omitted
+		switch *ipFamily {
+		case egv1a1.IPv6:
+			serviceSpec.IPFamilies = []corev1.IPFamily{corev1.IPv6Protocol}
+			serviceSpec.IPFamilyPolicy = ptr.To(corev1.IPFamilyPolicySingleStack)
+		case egv1a1.DualStack:
+			serviceSpec.IPFamilies = []corev1.IPFamily{corev1.IPv4Protocol, corev1.IPv6Protocol}
+			serviceSpec.IPFamilyPolicy = ptr.To(corev1.IPFamilyPolicyRequireDualStack)
+		}
+	}
+
 	svc := &corev1.Service{
 		TypeMeta: metav1.TypeMeta{
 			APIVersion: "v1",

internal/infrastructure/kubernetes/proxy/resource_provider_test.go

@@ -44,6 +44,16 @@ func newTestInfra() *ir.Infra {
 	return newTestInfraWithAnnotations(nil)
 }
 
+func newTestInfraWithIPFamily(family *egv1a1.IPFamily) *ir.Infra {
+	i := newTestInfra()
+	i.Proxy.Config = &egv1a1.EnvoyProxy{
+		Spec: egv1a1.EnvoyProxySpec{
+			IPFamily: family,
+		},
+	}
+	return i
+}
+
 func newTestIPv6Infra() *ir.Infra {
 	i := newTestInfra()
 	i.Proxy.Config = &egv1a1.EnvoyProxy{
@@ -1165,6 +1175,21 @@ func TestService(t *testing.T) {
 				Name: ptr.To("custom-service-name"),
 			},
 		},
+		{
+			caseName: "dualstack",
+			infra:    newTestInfraWithIPFamily(ptr.To(egv1a1.DualStack)),
+			service:  nil,
+		},
+		{
+			caseName: "ipv4-singlestack",
+			infra:    newTestInfraWithIPFamily(ptr.To(egv1a1.IPv4)),
+			service:  nil,
+		},
+		{
+			caseName: "ipv6-singlestack",
+			infra:    newTestInfraWithIPFamily(ptr.To(egv1a1.IPv6)),
+			service:  nil,
+		},
 	}
 	for _, tc := range cases {
 		t.Run(tc.caseName, func(t *testing.T) {
@@ -1536,3 +1561,48 @@ func TestOwningGatewayLabelsAbsent(t *testing.T) {
 		})
 	}
 }
+
+func TestIPFamilyPresentInSpec(t *testing.T) {
+	cases := []struct {
+		name             string
+		requestedFamily  *egv1a1.IPFamily
+		expectedFamilies []corev1.IPFamily
+		expectedPolicy   *corev1.IPFamilyPolicy
+	}{
+		{
+			"no family specified",
+			nil,
+			nil,
+			nil,
+		},
+		{
+			"ipv4 specified",
+			ptr.To(egv1a1.IPv4),
+			nil,
+			nil,
+		},
+		{
+			"ipv6 specified",
+			ptr.To(egv1a1.IPv6),
+			[]corev1.IPFamily{corev1.IPv6Protocol},
+			ptr.To(corev1.IPFamilyPolicySingleStack),
+		},
+		{
+			"dual stack",
+			ptr.To(egv1a1.DualStack),
+			[]corev1.IPFamily{corev1.IPv4Protocol, corev1.IPv6Protocol},
+			ptr.To(corev1.IPFamilyPolicyRequireDualStack),
+		},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			r := ResourceRender{infra: newTestInfraWithIPFamily(tc.requestedFamily).Proxy}
+			svc, err := r.Service()
+			require.NoError(t, err, "service render func")
+
+			assert.ElementsMatch(t, tc.expectedFamilies, svc.Spec.IPFamilies, "families slice")
+			assert.Equal(t, tc.expectedPolicy, svc.Spec.IPFamilyPolicy, "policy")
+		})
+	}
+}

internal/infrastructure/kubernetes/proxy/testdata/services/dualstack.yaml

@@ -0,0 +1,34 @@
+apiVersion: v1
+kind: Service
+metadata:
+  labels:
+    app.kubernetes.io/name: envoy
+    app.kubernetes.io/component: proxy
+    app.kubernetes.io/managed-by: envoy-gateway
+    gateway.envoyproxy.io/owning-gateway-name: default
+    gateway.envoyproxy.io/owning-gateway-namespace: default
+  name: envoy-default-37a8eec1
+  namespace: envoy-gateway-system
+spec:
+  externalTrafficPolicy: Local
+  ipFamilies:
+    - IPv4
+    - IPv6
+  ipFamilyPolicy: RequireDualStack
+  ports:
+    - name: EnvoyHTTPPort
+      port: 0
+      protocol: TCP
+      targetPort: 8080
+    - name: EnvoyHTTPSPort
+      port: 0
+      protocol: TCP
+      targetPort: 8443
+  selector:
+    app.kubernetes.io/name: envoy
+    app.kubernetes.io/component: proxy
+    app.kubernetes.io/managed-by: envoy-gateway
+    gateway.envoyproxy.io/owning-gateway-name: default
+    gateway.envoyproxy.io/owning-gateway-namespace: default
+  sessionAffinity: None
+  type: LoadBalancer

internal/infrastructure/kubernetes/proxy/testdata/services/ipv4-singlestack.yaml

@@ -0,0 +1,30 @@
+apiVersion: v1
+kind: Service
+metadata:
+  labels:
+    app.kubernetes.io/name: envoy
+    app.kubernetes.io/component: proxy
+    app.kubernetes.io/managed-by: envoy-gateway
+    gateway.envoyproxy.io/owning-gateway-name: default
+    gateway.envoyproxy.io/owning-gateway-namespace: default
+  name: envoy-default-37a8eec1
+  namespace: envoy-gateway-system
+spec:
+  externalTrafficPolicy: Local
+  ports:
+    - name: EnvoyHTTPPort
+      port: 0
+      protocol: TCP
+      targetPort: 8080
+    - name: EnvoyHTTPSPort
+      port: 0
+      protocol: TCP
+      targetPort: 8443
+  selector:
+    app.kubernetes.io/name: envoy
+    app.kubernetes.io/component: proxy
+    app.kubernetes.io/managed-by: envoy-gateway
+    gateway.envoyproxy.io/owning-gateway-name: default
+    gateway.envoyproxy.io/owning-gateway-namespace: default
+  sessionAffinity: None
+  type: LoadBalancer

internal/infrastructure/kubernetes/proxy/testdata/services/ipv6-singlestack.yaml

@@ -0,0 +1,33 @@
+apiVersion: v1
+kind: Service
+metadata:
+  labels:
+    app.kubernetes.io/name: envoy
+    app.kubernetes.io/component: proxy
+    app.kubernetes.io/managed-by: envoy-gateway
+    gateway.envoyproxy.io/owning-gateway-name: default
+    gateway.envoyproxy.io/owning-gateway-namespace: default
+  name: envoy-default-37a8eec1
+  namespace: envoy-gateway-system
+spec:
+  externalTrafficPolicy: Local
+  ipFamilies:
+    - IPv6
+  ipFamilyPolicy: SingleStack
+  ports:
+    - name: EnvoyHTTPPort
+      port: 0
+      protocol: TCP
+      targetPort: 8080
+    - name: EnvoyHTTPSPort
+      port: 0
+      protocol: TCP
+      targetPort: 8443
+  selector:
+    app.kubernetes.io/name: envoy
+    app.kubernetes.io/component: proxy
+    app.kubernetes.io/managed-by: envoy-gateway
+    gateway.envoyproxy.io/owning-gateway-name: default
+    gateway.envoyproxy.io/owning-gateway-namespace: default
+  sessionAffinity: None
+  type: LoadBalancer