Merge pull request #129798 from aojea/ipv6_alloc_dual_write

cluster ip allocator should check first on the legacy allocators

pkg/registry/core/service/ipallocator/cidrallocator.go

@@ -361,6 +361,20 @@ func (c *MetaAllocator) Allocate(ip net.IP) error {
 }
 
 func (c *MetaAllocator) AllocateNextService(service *api.Service) (net.IP, error) {
+	// If the cluster is still using the old allocators use them first to try to
+	// get an IP address to keep backwards compatibility.
+	if !utilfeature.DefaultFeatureGate.Enabled(features.DisableAllocatorDualWrite) {
+		ip, err := c.bitmapAllocator.AllocateNext()
+		if err == nil {
+			allocator, err := c.getAllocator(ip, true)
+			if err != nil {
+				return nil, err
+			}
+			return ip, allocator.AllocateService(service, ip)
+		} else {
+			klog.Infof("no IP address available on the old ClusterIP allocator, trying to get a new address using the new allocators")
+		}
+	}
 	c.mu.Lock()
 	defer c.mu.Unlock()
 	// TODO(aojea) add strategy to return a random allocator but
@@ -376,15 +390,6 @@ func (c *MetaAllocator) AllocateNextService(service *api.Service) (net.IP, error
 		}
 		ip, err := item.allocator.AllocateNextService(service)
 		if err == nil {
-			if !utilfeature.DefaultFeatureGate.Enabled(features.DisableAllocatorDualWrite) {
-				cidr := c.bitmapAllocator.CIDR()
-				if cidr.Contains(ip) {
-					err := c.bitmapAllocator.Allocate(ip)
-					if err != nil {
-						continue
-					}
-				}
-			}
 			return ip, nil
 		}
 	}

pkg/registry/core/service/ipallocator/cidrallocator_test.go

@@ -484,9 +484,6 @@ func TestCIDRAllocateDualWrite(t *testing.T) {
 	if f := r.Free(); f != 0 {
 		t.Errorf("free: %d", f)
 	}
-	if _, err := r.AllocateNext(); err == nil {
-		t.Error(err)
-	}
 
 	cidr := newServiceCIDR("test", "192.168.0.0/28")
 	_, err = r.client.ServiceCIDRs().Create(context.Background(), cidr, metav1.CreateOptions{})
@@ -554,9 +551,6 @@ func TestCIDRAllocateDualWriteCollision(t *testing.T) {
 	if f := r.Free(); f != 0 {
 		t.Errorf("free: %d", f)
 	}
-	if _, err := r.AllocateNext(); err == nil {
-		t.Error(err)
-	}
 
 	cidr := newServiceCIDR("test", "192.168.0.0/28")
 	_, err = r.client.ServiceCIDRs().Create(context.Background(), cidr, metav1.CreateOptions{})

test/integration/dualstack/dualstack_test.go

@@ -298,7 +298,7 @@ func TestCreateServiceSingleStackIPv6(t *testing.T) {
 					apiServerOptions,
 					[]string{
 						fmt.Sprintf("--runtime-config=networking.k8s.io/v1beta1=%v", enableMultiServiceCIDR),
-						"--service-cluster-ip-range=2001:db8:1::/112",
+						"--service-cluster-ip-range=2001:db8:1::/108",
 						"--advertise-address=2001:db8::10",
 						"--disable-admission-plugins=ServiceAccount",
 						fmt.Sprintf("--feature-gates=%s=%v,%s=%v", features.MultiCIDRServiceAllocator, enableMultiServiceCIDR, features.DisableAllocatorDualWrite, disableAllocatorDualWrite),
@@ -529,7 +529,7 @@ func TestCreateServiceDualStackIPv4IPv6(t *testing.T) {
 					apiServerOptions,
 					[]string{
 						fmt.Sprintf("--runtime-config=networking.k8s.io/v1beta1=%v", enableMultiServiceCIDR),
-						"--service-cluster-ip-range=10.0.0.0/16,2001:db8:1::/112",
+						"--service-cluster-ip-range=10.0.0.0/16,2001:db8:1::/108",
 						"--advertise-address=10.0.0.1",
 						"--disable-admission-plugins=ServiceAccount",
 						fmt.Sprintf("--feature-gates=%s=%v,%s=%v", features.MultiCIDRServiceAllocator, enableMultiServiceCIDR, features.DisableAllocatorDualWrite, disableAllocatorDualWrite),
@@ -808,7 +808,7 @@ func TestCreateServiceDualStackIPv6IPv4(t *testing.T) {
 					apiServerOptions,
 					[]string{
 						fmt.Sprintf("--runtime-config=networking.k8s.io/v1beta1=%v", enableMultiServiceCIDR),
-						"--service-cluster-ip-range=2001:db8:1::/112,10.0.0.0/16",
+						"--service-cluster-ip-range=2001:db8:1::/108,10.0.0.0/16",
 						"--advertise-address=2001:db8::10",
 						"--disable-admission-plugins=ServiceAccount",
 						fmt.Sprintf("--feature-gates=%s=%v,%s=%v", features.MultiCIDRServiceAllocator, enableMultiServiceCIDR, features.DisableAllocatorDualWrite, disableAllocatorDualWrite),
@@ -1038,7 +1038,7 @@ func TestUpgradeDowngrade(t *testing.T) {
 	s := kubeapiservertesting.StartTestServerOrDie(t,
 		apiServerOptions,
 		[]string{
-			"--service-cluster-ip-range=10.0.0.0/16,2001:db8:1::/112",
+			"--service-cluster-ip-range=10.0.0.0/16,2001:db8:1::/108",
 			"--advertise-address=10.0.0.1",
 			"--disable-admission-plugins=ServiceAccount",
 		},
@@ -1149,7 +1149,7 @@ func TestConvertToFromExternalName(t *testing.T) {
 	s := kubeapiservertesting.StartTestServerOrDie(t,
 		apiServerOptions,
 		[]string{
-			"--service-cluster-ip-range=10.0.0.0/16,2001:db8:1::/112",
+			"--service-cluster-ip-range=10.0.0.0/16,2001:db8:1::/108",
 			"--advertise-address=10.0.0.1",
 			"--disable-admission-plugins=ServiceAccount",
 		},
@@ -1238,7 +1238,7 @@ func TestPreferDualStack(t *testing.T) {
 	s := kubeapiservertesting.StartTestServerOrDie(t,
 		apiServerOptions,
 		[]string{
-			"--service-cluster-ip-range=10.0.0.0/16,2001:db8:1::/112",
+			"--service-cluster-ip-range=10.0.0.0/16,2001:db8:1::/108",
 			"--advertise-address=10.0.0.1",
 			"--disable-admission-plugins=ServiceAccount",
 		},
@@ -1552,7 +1552,7 @@ func TestUpgradeServicePreferToDualStack(t *testing.T) {
 	s = kubeapiservertesting.StartTestServerOrDie(t,
 		apiServerOptions,
 		[]string{
-			"--service-cluster-ip-range=192.168.0.0/24,2001:db8:1::/112",
+			"--service-cluster-ip-range=192.168.0.0/24,2001:db8:1::/108",
 			"--disable-admission-plugins=ServiceAccount",
 		},
 		sharedEtcd)
@@ -1593,7 +1593,7 @@ func TestDowngradeServicePreferToDualStack(t *testing.T) {
 	s := kubeapiservertesting.StartTestServerOrDie(t,
 		apiServerOptions,
 		[]string{
-			"--service-cluster-ip-range=192.168.0.0/24,2001:db8:1::/112",
+			"--service-cluster-ip-range=192.168.0.0/24,2001:db8:1::/108",
 			"--advertise-address=10.0.0.1",
 			"--disable-admission-plugins=ServiceAccount",
 		},