⚠️ Change .status.replicas fields to pointer + omitempty

api/v1beta1/conversion_test.go

@@ -275,6 +275,11 @@ func hubMachineSetStatus(in *clusterv1.MachineSetStatus, c fuzz.Continue) {
 	if in.Deprecated.V1Beta1 == nil {
 		in.Deprecated.V1Beta1 = &clusterv1.MachineSetV1Beta1DeprecatedStatus{}
 	}
+	// nil becomes &0 after hub => spoke => hub conversion
+	// This is acceptable as usually Replicas is set and controllers using older apiVersions are not writing MachineSet status.
+	if in.Replicas == nil {
+		in.Replicas = ptr.To(int32(0))
+	}
 }
 
 func spokeMachineSetStatus(in *MachineSetStatus, c fuzz.Continue) {
@@ -304,6 +309,11 @@ func hubMachineDeploymentStatus(in *clusterv1.MachineDeploymentStatus, c fuzz.Co
 	if in.Deprecated.V1Beta1 == nil {
 		in.Deprecated.V1Beta1 = &clusterv1.MachineDeploymentV1Beta1DeprecatedStatus{}
 	}
+	// nil becomes &0 after hub => spoke => hub conversion
+	// This is acceptable as usually Replicas is set and controllers using older apiVersions are not writing MachineSet status.
+	if in.Replicas == nil {
+		in.Replicas = ptr.To(int32(0))
+	}
 }
 
 func spokeMachineDeploymentSpec(in *MachineDeploymentSpec, c fuzz.Continue) {

api/v1beta2/machinedeployment_types.go

@@ -463,7 +463,7 @@ type MachineDeploymentStatus struct {
 	// replicas is the total number of non-terminated machines targeted by this deployment
 	// (their labels match the selector).
 	// +optional
-	Replicas int32 `json:"replicas"`
+	Replicas *int32 `json:"replicas,omitempty"`
 
 	// readyReplicas is the number of ready replicas for this MachineDeployment. A machine is considered ready when Machine's Ready condition is true.
 	// +optional

api/v1beta2/machineset_types.go

@@ -301,7 +301,7 @@ type MachineSetStatus struct {
 
 	// replicas is the most recently observed number of replicas.
 	// +optional
-	Replicas int32 `json:"replicas"`
+	Replicas *int32 `json:"replicas,omitempty"`
 
 	// readyReplicas is the number of ready replicas for this MachineSet. A machine is considered ready when Machine's Ready condition is true.
 	// +optional

controlplane/kubeadm/api/v1beta1/conversion_test.go

@@ -25,6 +25,7 @@ import (
 	fuzz "github.com/google/gofuzz"
 	"k8s.io/apimachinery/pkg/api/apitesting/fuzzer"
 	runtimeserializer "k8s.io/apimachinery/pkg/runtime/serializer"
+	"k8s.io/utils/ptr"
 
 	bootstrapv1beta1 "sigs.k8s.io/cluster-api/bootstrap/kubeadm/api/v1beta1"
 	controlplanev1 "sigs.k8s.io/cluster-api/controlplane/kubeadm/api/v1beta2"
@@ -70,6 +71,12 @@ func hubKubeadmControlPlaneStatus(in *controlplanev1.KubeadmControlPlaneStatus,
 			in.Initialization = nil
 		}
 	}
+
+	// nil becomes &0 after hub => spoke => hub conversion
+	// This is acceptable as usually Replicas is set and controllers using older apiVersions are not writing MachineSet status.
+	if in.Replicas == nil {
+		in.Replicas = ptr.To(int32(0))
+	}
 }
 
 func spokeKubeadmControlPlaneStatus(in *KubeadmControlPlaneStatus, c fuzz.Continue) {

controlplane/kubeadm/api/v1beta2/kubeadm_control_plane_types.go

@@ -650,7 +650,7 @@ type KubeadmControlPlaneStatus struct {
 	// replicas is the total number of non-terminated machines targeted by this control plane
 	// (their labels match the selector).
 	// +optional
-	Replicas int32 `json:"replicas"`
+	Replicas *int32 `json:"replicas,omitempty"`
 
 	// readyReplicas is the number of ready replicas for this KubeadmControlPlane. A machine is considered ready when Machine's Ready condition is true.
 	// +optional

controlplane/kubeadm/internal/controllers/controller_test.go

@@ -1385,7 +1385,7 @@ kubernetesVersion: metav1.16.1
 		g.Expect(kcp.Finalizers).To(ContainElement(controlplanev1.KubeadmControlPlaneFinalizer))
 
 		g.Expect(kcp.Status.Selector).NotTo(BeEmpty())
-		g.Expect(kcp.Status.Replicas).To(BeEquivalentTo(1))
+		g.Expect(kcp.Status.Replicas).To(HaveValue(BeEquivalentTo(1)))
 		g.Expect(v1beta1conditions.IsFalse(kcp, controlplanev1.AvailableV1Beta1Condition)).To(BeTrue())
 		g.Expect(conditions.IsFalse(kcp, controlplanev1.KubeadmControlPlaneInitializedCondition)).To(BeTrue())
 
@@ -1626,7 +1626,7 @@ kubernetesVersion: metav1.16.1`,
 		g.Expect(kcp.Finalizers).To(ContainElement(controlplanev1.KubeadmControlPlaneFinalizer))
 
 		g.Expect(kcp.Status.Selector).NotTo(BeEmpty())
-		g.Expect(kcp.Status.Replicas).To(BeEquivalentTo(1))
+		g.Expect(kcp.Status.Replicas).To(HaveValue(BeEquivalentTo(1)))
 		g.Expect(v1beta1conditions.IsFalse(kcp, controlplanev1.AvailableV1Beta1Condition)).To(BeTrue())
 
 		// Verify that the kubeconfig is using the custom CA

controlplane/kubeadm/internal/controllers/status.go

@@ -188,7 +188,7 @@ func setReplicas(_ context.Context, kcp *controlplanev1.KubeadmControlPlane, mac
 		}
 	}
 
-	kcp.Status.Replicas = int32(len(machines))
+	kcp.Status.Replicas = ptr.To(int32(len(machines)))
 	kcp.Status.ReadyReplicas = ptr.To(readyReplicas)
 	kcp.Status.AvailableReplicas = ptr.To(availableReplicas)
 	kcp.Status.UpToDateReplicas = ptr.To(upToDateReplicas)

controlplane/kubeadm/internal/controllers/status_test.go

@@ -130,7 +130,8 @@ func TestSetReplicas(t *testing.T) {
 	setReplicas(ctx, c.KCP, c.Machines)
 
 	g.Expect(kcp.Status).ToNot(BeNil())
-	g.Expect(kcp.Status.Replicas).To(Equal(int32(6)))
+	g.Expect(kcp.Status.Replicas).ToNot(BeNil())
+	g.Expect(*kcp.Status.Replicas).To(Equal(int32(6)))
 	g.Expect(kcp.Status.ReadyReplicas).ToNot(BeNil())
 	g.Expect(*kcp.Status.ReadyReplicas).To(Equal(int32(3)))
 	g.Expect(kcp.Status.AvailableReplicas).ToNot(BeNil())
@@ -304,7 +305,7 @@ func Test_setScalingUpCondition(t *testing.T) {
 			controlPlane: &internal.ControlPlane{
 				KCP: &controlplanev1.KubeadmControlPlane{
 					Spec:   controlplanev1.KubeadmControlPlaneSpec{Replicas: ptr.To(int32(3))},
-					Status: controlplanev1.KubeadmControlPlaneStatus{Replicas: 3},
+					Status: controlplanev1.KubeadmControlPlaneStatus{Replicas: ptr.To(int32(3))},
 				},
 				Machines: collections.FromMachines(
 					&clusterv1.Machine{ObjectMeta: metav1.ObjectMeta{Name: "m1"}},
@@ -323,7 +324,7 @@ func Test_setScalingUpCondition(t *testing.T) {
 			controlPlane: &internal.ControlPlane{
 				KCP: &controlplanev1.KubeadmControlPlane{
 					Spec:   controlplanev1.KubeadmControlPlaneSpec{Replicas: ptr.To(int32(3)), MachineTemplate: controlplanev1.KubeadmControlPlaneMachineTemplate{InfrastructureRef: corev1.ObjectReference{Kind: "AWSTemplate"}}},
-					Status: controlplanev1.KubeadmControlPlaneStatus{Replicas: 3},
+					Status: controlplanev1.KubeadmControlPlaneStatus{Replicas: ptr.To(int32(3))},
 				},
 				Machines: collections.FromMachines(
 					&clusterv1.Machine{ObjectMeta: metav1.ObjectMeta{Name: "m1"}},
@@ -344,7 +345,7 @@ func Test_setScalingUpCondition(t *testing.T) {
 			controlPlane: &internal.ControlPlane{
 				KCP: &controlplanev1.KubeadmControlPlane{
 					Spec:   controlplanev1.KubeadmControlPlaneSpec{Replicas: ptr.To(int32(5))},
-					Status: controlplanev1.KubeadmControlPlaneStatus{Replicas: 3},
+					Status: controlplanev1.KubeadmControlPlaneStatus{Replicas: ptr.To(int32(3))},
 				},
 				Machines: collections.FromMachines(
 					&clusterv1.Machine{ObjectMeta: metav1.ObjectMeta{Name: "m1"}},
@@ -365,7 +366,7 @@ func Test_setScalingUpCondition(t *testing.T) {
 				KCP: &controlplanev1.KubeadmControlPlane{
 					ObjectMeta: metav1.ObjectMeta{DeletionTimestamp: ptr.To(metav1.Time{Time: time.Now()})},
 					Spec:       controlplanev1.KubeadmControlPlaneSpec{Replicas: ptr.To(int32(5))},
-					Status:     controlplanev1.KubeadmControlPlaneStatus{Replicas: 3},
+					Status:     controlplanev1.KubeadmControlPlaneStatus{Replicas: ptr.To(int32(3))},
 				},
 				Machines: collections.FromMachines(
 					&clusterv1.Machine{ObjectMeta: metav1.ObjectMeta{Name: "m1"}},
@@ -384,7 +385,7 @@ func Test_setScalingUpCondition(t *testing.T) {
 			controlPlane: &internal.ControlPlane{
 				KCP: &controlplanev1.KubeadmControlPlane{
 					Spec:   controlplanev1.KubeadmControlPlaneSpec{Replicas: ptr.To(int32(5)), MachineTemplate: controlplanev1.KubeadmControlPlaneMachineTemplate{InfrastructureRef: corev1.ObjectReference{Kind: "AWSTemplate"}}},
-					Status: controlplanev1.KubeadmControlPlaneStatus{Replicas: 3},
+					Status: controlplanev1.KubeadmControlPlaneStatus{Replicas: ptr.To(int32(3))},
 				},
 				Machines: collections.FromMachines(
 					&clusterv1.Machine{ObjectMeta: metav1.ObjectMeta{Name: "m1"}},
@@ -413,7 +414,7 @@ func Test_setScalingUpCondition(t *testing.T) {
 				},
 				KCP: &controlplanev1.KubeadmControlPlane{
 					Spec:   controlplanev1.KubeadmControlPlaneSpec{Replicas: ptr.To(int32(5))},
-					Status: controlplanev1.KubeadmControlPlaneStatus{Replicas: 3},
+					Status: controlplanev1.KubeadmControlPlaneStatus{Replicas: ptr.To(int32(3))},
 				},
 				Machines: collections.FromMachines(
 					&clusterv1.Machine{ObjectMeta: metav1.ObjectMeta{Name: "m1"}},
@@ -475,7 +476,7 @@ func Test_setScalingDownCondition(t *testing.T) {
 			controlPlane: &internal.ControlPlane{
 				KCP: &controlplanev1.KubeadmControlPlane{
 					Spec:   controlplanev1.KubeadmControlPlaneSpec{Replicas: ptr.To(int32(3))},
-					Status: controlplanev1.KubeadmControlPlaneStatus{Replicas: 3},
+					Status: controlplanev1.KubeadmControlPlaneStatus{Replicas: ptr.To(int32(3))},
 				},
 				Machines: collections.FromMachines(
 					&clusterv1.Machine{ObjectMeta: metav1.ObjectMeta{Name: "m1"}},
@@ -494,7 +495,7 @@ func Test_setScalingDownCondition(t *testing.T) {
 			controlPlane: &internal.ControlPlane{
 				KCP: &controlplanev1.KubeadmControlPlane{
 					Spec:   controlplanev1.KubeadmControlPlaneSpec{Replicas: ptr.To(int32(3))},
-					Status: controlplanev1.KubeadmControlPlaneStatus{Replicas: 5},
+					Status: controlplanev1.KubeadmControlPlaneStatus{Replicas: ptr.To(int32(5))},
 				},
 				Machines: collections.FromMachines(
 					&clusterv1.Machine{ObjectMeta: metav1.ObjectMeta{Name: "m1"}},
@@ -517,7 +518,7 @@ func Test_setScalingDownCondition(t *testing.T) {
 				KCP: &controlplanev1.KubeadmControlPlane{
 					ObjectMeta: metav1.ObjectMeta{DeletionTimestamp: ptr.To(metav1.Time{Time: time.Now()})},
 					Spec:       controlplanev1.KubeadmControlPlaneSpec{Replicas: ptr.To(int32(3))},
-					Status:     controlplanev1.KubeadmControlPlaneStatus{Replicas: 5},
+					Status:     controlplanev1.KubeadmControlPlaneStatus{Replicas: ptr.To(int32(5))},
 				},
 				Machines: collections.FromMachines(
 					&clusterv1.Machine{ObjectMeta: metav1.ObjectMeta{Name: "m1"}},
@@ -539,7 +540,7 @@ func Test_setScalingDownCondition(t *testing.T) {
 			controlPlane: &internal.ControlPlane{
 				KCP: &controlplanev1.KubeadmControlPlane{
 					Spec:   controlplanev1.KubeadmControlPlaneSpec{Replicas: ptr.To(int32(1))},
-					Status: controlplanev1.KubeadmControlPlaneStatus{Replicas: 3},
+					Status: controlplanev1.KubeadmControlPlaneStatus{Replicas: ptr.To(int32(3))},
 				},
 				Machines: collections.FromMachines(
 					&clusterv1.Machine{ObjectMeta: metav1.ObjectMeta{Name: "m1", DeletionTimestamp: ptr.To(metav1.Time{Time: time.Now().Add(-1 * time.Hour)})},
@@ -579,7 +580,7 @@ After above Pods have been removed from the Node, the following Pods will be evi
 			controlPlane: &internal.ControlPlane{
 				KCP: &controlplanev1.KubeadmControlPlane{
 					Spec:   controlplanev1.KubeadmControlPlaneSpec{Replicas: ptr.To(int32(1))},
-					Status: controlplanev1.KubeadmControlPlaneStatus{Replicas: 3},
+					Status: controlplanev1.KubeadmControlPlaneStatus{Replicas: ptr.To(int32(3))},
 				},
 				Machines: collections.FromMachines(
 					&clusterv1.Machine{ObjectMeta: metav1.ObjectMeta{Name: "m1", DeletionTimestamp: ptr.To(metav1.Time{Time: time.Now().Add(-1 * time.Hour)})}},
@@ -607,7 +608,7 @@ After above Pods have been removed from the Node, the following Pods will be evi
 				},
 				KCP: &controlplanev1.KubeadmControlPlane{
 					Spec:   controlplanev1.KubeadmControlPlaneSpec{Replicas: ptr.To(int32(1))},
-					Status: controlplanev1.KubeadmControlPlaneStatus{Replicas: 3},
+					Status: controlplanev1.KubeadmControlPlaneStatus{Replicas: ptr.To(int32(3))},
 				},
 				Machines: collections.FromMachines(
 					&clusterv1.Machine{ObjectMeta: metav1.ObjectMeta{Name: "m1"}},

docs/book/src/developer/providers/migrations/v1.10-to-v1.11.md

@@ -98,6 +98,7 @@ proposal because most of the changes described below are a consequence of the wo
 - See changes that apply to [all CRDs](#all-crds)
 - The `spec.progressDeadlineSeconds` field (deprecated since CAPI v1.9) has been removed
 - Replica counters are now consistent with replica counters from other resources
+  - `status.replicas` was made a pointer and omitempty was added
   - `status.readyReplicas` has now a new semantic based on machine's `Ready` condition
   - `status.availableReplicas` has now a new semantic based on machine's `Available` condition
   - `status.upToDateReplicas` has now a new semantic (and name) based on machine's `UpToDate` condition
@@ -111,6 +112,7 @@ proposal because most of the changes described below are a consequence of the wo
 
 - See changes that apply to [all CRDs](#all-crds)
 - Replica counters fields are now consistent with replica counters from other resources
+  - `status.replicas` was made a pointer and omitempty was added
   - `status.readyReplicas` has now a new semantic based on machine's `Ready` condition
   - `status.availableReplicas` has now a new semantic based on machine's `Available` condition
   - `status.upToDateReplicas` has now a new semantic (and name) based on machine's `UpToDate` condition
@@ -121,6 +123,7 @@ proposal because most of the changes described below are a consequence of the wo
 ### MachinePool
 
 - See changes that apply to [all CRDs](#all-crds)
+- `status.replicas` was made a pointer and omitempty was added
 - Support for terminal errors has been dropped.
   - `status.failureReason` and `status.failureMessage` will continue to exist temporarily under `status.deprecated.v1beta1`.
   - The const values for `Failed` phase has been deprecated in the enum type for `status.phase` (controllers are not setting this value anymore)
@@ -165,6 +168,7 @@ proposal because most of the changes described below are a consequence of the wo
 - KubeadmControlPlane (and the entire KCP provider) now implements the v1beta2 Cluster API contract.
 - See changes that apply to [all CRDs](#all-crds)
 - Replica counters fields are now consistent with replica counters from other resources.
+  - `status.replicas` was made a pointer and omitempty was added
   - `status.readyReplicas` has now a new semantic based on machine's `Ready` condition
   - `status.availableReplicas` has now a new semantic based on machine's `Available` condition
   - `status.upToDateReplicas` has now a new semantic (and name) based on machine's `UpToDate` condition

exp/api/v1beta1/conversion_test.go

@@ -25,6 +25,7 @@ import (
 	fuzz "github.com/google/gofuzz"
 	"k8s.io/apimachinery/pkg/api/apitesting/fuzzer"
 	runtimeserializer "k8s.io/apimachinery/pkg/runtime/serializer"
+	"k8s.io/utils/ptr"
 
 	expv1 "sigs.k8s.io/cluster-api/exp/api/v1beta2"
 	utilconversion "sigs.k8s.io/cluster-api/util/conversion"
@@ -63,6 +64,12 @@ func hubMachinePoolStatus(in *expv1.MachinePoolStatus, c fuzz.Continue) {
 			in.Initialization = nil
 		}
 	}
+
+	// nil becomes &0 after hub => spoke => hub conversion
+	// This is acceptable as usually Replicas is set and controllers using older apiVersions are not writing MachineSet status.
+	if in.Replicas == nil {
+		in.Replicas = ptr.To(int32(0))
+	}
 }
 
 func spokeMachinePoolStatus(in *MachinePoolStatus, c fuzz.Continue) {