Merge pull request #8574 from k8s-infra-cherrypick-robot/cherry-pick-…

…8506-to-release-1.4

[release-1.4] 🐛 ipam: fix gateway being required for IPAddress

exp/ipam/api/v1alpha1/ipaddress_types.go

@@ -36,7 +36,8 @@ type IPAddressSpec struct {
 	Prefix int `json:"prefix"`
 
 	// Gateway is the network gateway of the network the address is from.
-	Gateway string `json:"gateway"`
+	// +optional
+	Gateway string `json:"gateway,omitempty"`
 }
 
 // +kubebuilder:object:root=true

exp/ipam/internal/webhooks/ipaddress.go

@@ -123,14 +123,15 @@ func (webhook *IPAddress) validate(ctx context.Context, ip *ipamv1.IPAddress) er
 			))
 	}
 
-	_, err = netip.ParseAddr(ip.Spec.Gateway)
-	if err != nil {
-		allErrs = append(allErrs,
-			field.Invalid(
-				specPath.Child("gateway"),
-				ip.Spec.Gateway,
-				"not a valid IP address",
-			))
+	if ip.Spec.Gateway != "" {
+		if _, err := netip.ParseAddr(ip.Spec.Gateway); err != nil {
+			allErrs = append(allErrs,
+				field.Invalid(
+					specPath.Child("gateway"),
+					ip.Spec.Gateway,
+					"not a valid IP address",
+				))
+		}
 	}
 
 	if ip.Spec.PoolRef.APIGroup == nil {

exp/ipam/internal/webhooks/ipaddress_test.go

@@ -130,6 +130,14 @@ func TestIPAddressValidateCreate(t *testing.T) {
 			extraObjs: []client.Object{claim},
 			expectErr: true,
 		},
+		{
+			name: "an empty gateway should be allowed",
+			ip: getAddress(false, func(addr *ipamv1.IPAddress) {
+				addr.Spec.Gateway = ""
+			}),
+			extraObjs: []client.Object{claim},
+			expectErr: false,
+		},
 		{
 			name: "a pool reference that does not match the claim should be rejected",
 			ip: getAddress(false, func(addr *ipamv1.IPAddress) {