fix: fix validation and wording when making gateway spec addresses value optional

apis/v1/gateway_types.go

@@ -246,7 +246,7 @@ type GatewaySpec struct {
 	// Addresses requested for this Gateway. This is optional and behavior can
 	// depend on the implementation. If a value is set in the spec and the
 	// requested address is invalid or unavailable, the implementation MUST
-	// indicate this in the associated entry in GatewayStatus.Addresses.
+	// indicate this in an associated entry in GatewayStatus.Conditions.
 	//
 	// The Addresses field represents a request for the address(es) on the
 	// "outside of the Gateway", that traffic bound for this Gateway will use.
@@ -268,8 +268,8 @@ type GatewaySpec struct {
 	// +listType=atomic
 	// <gateway:validateIPAddress>
 	// +kubebuilder:validation:MaxItems=16
-	// +kubebuilder:validation:XValidation:message="IPAddress values must be unique",rule="self.all(a1, a1.type == 'IPAddress' ? self.exists_one(a2, a2.type == a1.type && a2.value == a1.value) : true )"
-	// +kubebuilder:validation:XValidation:message="Hostname values must be unique",rule="self.all(a1, a1.type == 'Hostname' ? self.exists_one(a2, a2.type == a1.type && a2.value == a1.value) : true )"
+	// +kubebuilder:validation:XValidation:message="IPAddress values must be unique",rule="self.all(a1, a1.type == 'IPAddress' && has(a1.value) ? self.exists_one(a2, a2.type == a1.type && has(a2.value) && a2.value == a1.value) : true )"
+	// +kubebuilder:validation:XValidation:message="Hostname values must be unique",rule="self.all(a1, a1.type == 'Hostname'  && has(a1.value) ? self.exists_one(a2, a2.type == a1.type && has(a2.value) && a2.value == a1.value) : true )"
 	Addresses []GatewaySpecAddress `json:"addresses,omitempty"`
 
 	// Infrastructure defines infrastructure level attributes about this Gateway instance.
@@ -884,7 +884,7 @@ type RouteGroupKind struct {
 
 // GatewaySpecAddress describes an address that can be bound to a Gateway.
 //
-// +kubebuilder:validation:XValidation:message="Hostname value must only contain valid characters (matching ^(\\*\\.)?[a-z0-9]([-a-z0-9]*[a-z0-9])?(\\.[a-z0-9]([-a-z0-9]*[a-z0-9])?)*$)",rule="self.type == 'Hostname' ? self.value.matches(r\"\"\"^(\\*\\.)?[a-z0-9]([-a-z0-9]*[a-z0-9])?(\\.[a-z0-9]([-a-z0-9]*[a-z0-9])?)*$\"\"\"): true"
+// +kubebuilder:validation:XValidation:message="Hostname value must be empty or contain only valid characters (matching ^(\\*\\.)?[a-z0-9]([-a-z0-9]*[a-z0-9])?(\\.[a-z0-9]([-a-z0-9]*[a-z0-9])?)*$)",rule="self.type == 'Hostname' ? (!has(self.value) || self.value.matches(r\"\"\"^(\\*\\.)?[a-z0-9]([-a-z0-9]*[a-z0-9])?(\\.[a-z0-9]([-a-z0-9]*[a-z0-9])?)*$\"\"\")): true"
 type GatewaySpecAddress struct {
 	// Type of the address.
 	//

conformance/tests/gateway-static-addresses.go

@@ -135,8 +135,8 @@ var GatewayStaticAddresses = suite.ConformanceTest{
 		kubernetes.GatewayStatusMustHaveListeners(t, s.Client, s.TimeoutConfig, gwNN, finalExpectedListenerState)
 		require.Len(t, currentGW.Spec.Addresses, 1, "expected only 1 address left specified on Gateway")
 		statusAddresses := extractStatusAddresses(currentGW.Status.Addresses)
-		require.NotContains(t, statusAddresses, unusableAddress.Value, "should contain the unusable address")
-		require.NotContains(t, statusAddresses, invalidAddress.Value, "should contain the invalid address")
+		require.NotContains(t, statusAddresses, unusableAddress.Value, "should not contain the unusable address")
+		require.NotContains(t, statusAddresses, invalidAddress.Value, "should not contain the invalid address")
 		require.Contains(t, statusAddresses, usableAddress.Value, "should contain the usable address")
 		for _, addr := range currentGW.Status.Addresses {
 			if usableAddress.Value != addr.Value {

pkg/test/cel/gateway_test.go

@@ -584,6 +584,54 @@ func TestValidateGateway(t *testing.T) {
 			},
 			wantErrors: []string{"IPAddress values must be unique", "Hostname values must be unique"},
 		},
+		{
+			desc: "optional ip address or hostname values",
+			mutate: func(gw *gatewayv1.Gateway) {
+				gw.Spec.Addresses = []gatewayv1.GatewaySpecAddress{
+					{
+						Type: ptrTo(gatewayv1.IPAddressType),
+					},
+					{
+						Type: ptrTo(gatewayv1.HostnameAddressType),
+					},
+				}
+			},
+		},
+		{
+			desc: "multiple optional ip address or hostname values alongside defined values",
+			mutate: func(gw *gatewayv1.Gateway) {
+				gw.Spec.Addresses = []gatewayv1.GatewaySpecAddress{
+					{
+						Type: ptrTo(gatewayv1.HostnameAddressType),
+					},
+					{
+						Type: ptrTo(gatewayv1.IPAddressType),
+					},
+					{
+						Type:  ptrTo(gatewayv1.IPAddressType),
+						Value: "1.2.3.4",
+					},
+					{
+						Type:  ptrTo(gatewayv1.HostnameAddressType),
+						Value: "foo.bar",
+					},
+					{
+						Type: ptrTo(gatewayv1.IPAddressType),
+					},
+					{
+						Type: ptrTo(gatewayv1.HostnameAddressType),
+					},
+					{
+						Type:  ptrTo(gatewayv1.IPAddressType),
+						Value: "2.3.4.5",
+					},
+					{
+						Type:  ptrTo(gatewayv1.HostnameAddressType),
+						Value: "bar.bar",
+					},
+				}
+			},
+		},
 	}
 
 	for _, tc := range testCases {