OCPBUGS-86306: Stop controllers fighting over HCP status

control-plane-operator/controllers/hostedcontrolplane/hostedcontrolplane_controller.go

@@ -1998,10 +1998,11 @@ func (r *HostedControlPlaneReconciler) reconcileValidIDPConfigurationCondition(c
 			Message: fmt.Sprintf("failed to initialize identity providers: %v", err),
 		}
 	}
-	// Update the condition on the HCP if it has changed
+	// Patch the condition on the HCP if it has changed
+	originalHCP := hcp.DeepCopy()
 	if meta.SetStatusCondition(&hcp.Status.Conditions, new) {
-		if err := r.Status().Update(ctx, hcp); err != nil {
-			return fmt.Errorf("failed to update valid IDP configuration condition: %w", err)
+		if err := r.Status().Patch(ctx, hcp, client.MergeFromWithOptions(originalHCP, client.MergeFromWithOptimisticLock{})); err != nil {
+			return fmt.Errorf("failed to patch valid IDP configuration condition: %w", err)
 		}
 	}
 	return nil
@@ -2518,14 +2519,15 @@ func (r *HostedControlPlaneReconciler) removeCloudResources(ctx context.Context,
 			if resourcesDestroyedCond != nil && resourcesDestroyedCond.Message != "" {
 				message = fmt.Sprintf("%s (last status: %s)", message, resourcesDestroyedCond.Message)
 			}
+			originalHCP := hcp.DeepCopy()
 			meta.SetStatusCondition(&hcp.Status.Conditions, metav1.Condition{
 				Type:    string(hyperv1.CloudResourcesDestroyed),
 				Status:  metav1.ConditionFalse,
 				Reason:  string(hyperv1.CloudResourcesDeletionTimedOutReason),
 				Message: message,
 			})
-			if err := r.Status().Update(ctx, hcp); err != nil {
-				return false, fmt.Errorf("failed to update cloud resources destroyed condition: %w", err)
+			if err := r.Status().Patch(ctx, hcp, client.MergeFromWithOptions(originalHCP, client.MergeFromWithOptimisticLock{})); err != nil {
+				return false, fmt.Errorf("failed to patch cloud resources destroyed condition: %w", err)
 			}
 			return true, nil
 		}
@@ -2550,15 +2552,16 @@ func (r *HostedControlPlaneReconciler) removeCloudResources(ctx context.Context,
 		return false, nil
 	}
 	if cvoScaledDownCond == nil || cvoScaledDownCond.Status != metav1.ConditionTrue {
+		originalHCP := hcp.DeepCopy()
 		cvoScaledDownCond = &metav1.Condition{
 			Type:               string(hyperv1.CVOScaledDown),
 			Status:             metav1.ConditionTrue,
 			Reason:             "CVOScaledDown",
 			LastTransitionTime: metav1.Now(),
 		}
 		meta.SetStatusCondition(&hcp.Status.Conditions, *cvoScaledDownCond)
-		if err := r.Status().Update(ctx, hcp); err != nil {
-			return false, fmt.Errorf("failed to set CVO scaled down condition: %w", err)
+		if err := r.Status().Patch(ctx, hcp, client.MergeFromWithOptions(originalHCP, client.MergeFromWithOptimisticLock{})); err != nil {
+			return false, fmt.Errorf("failed to patch CVO scaled down condition: %w", err)
 		}
 	}
 	return false, nil

control-plane-operator/hostedclusterconfigoperator/controllers/hcpstatus/hcpstatus.go

@@ -1,16 +1,18 @@
 package hcpstatus
 
 import (
+	"bytes"
 	"context"
+	"encoding/json"
 	"fmt"
-	"reflect"
 
 	hyperv1 "github.com/openshift/hypershift/api/hypershift/v1beta1"
 	"github.com/openshift/hypershift/control-plane-operator/hostedclusterconfigoperator/operator"
 	"github.com/openshift/hypershift/support/releaseinfo"
 
 	configv1 "github.com/openshift/api/config/v1"
 
+	"k8s.io/apimachinery/pkg/api/equality"
 	"k8s.io/apimachinery/pkg/api/meta"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/types"
@@ -74,17 +76,76 @@ func (h *hcpStatusReconciler) Reconcile(ctx context.Context, req reconcile.Reque
 		return reconcile.Result{}, err
 	}
 
-	if !reflect.DeepEqual(hcp.Status, originalHCP.Status) {
-		log.Info("Updating HCP status with new configuration and version status")
-		if err := h.mgtClusterClient.Status().Update(ctx, hcp); err != nil {
-			return reconcile.Result{}, fmt.Errorf("failed to update hcp: %w", err)
-		}
-		log.Info("Successfully updated HCP status")
+	if equality.Semantic.DeepEqual(hcp.Status, originalHCP.Status) {
+		return reconcile.Result{}, nil
+	}
+
+	// Use JSON Patch (RFC 6902) instead of JSON Merge Patch (RFC 7386).
+	// Merge patch interprets null as "delete field" (RFC 7386 §7), which corrupts
+	// +required +nullable fields in configv1.ClusterVersionStatus that have no
+	// omitempty and serialize nil as JSON null:
+	//   - AvailableUpdates []configv1.Release `json:"availableUpdates"` — nil slice → null
+	//   - CompletionTime *metav1.Time `json:"completionTime"` (in UpdateHistory) — nil pointer → null
+	// JSON Patch "replace"/"add" ops carry null as a literal value, preserving it correctly.
+	patch, err := buildStatusPatch(originalHCP, hcp)
+	if err != nil {
+		return reconcile.Result{}, fmt.Errorf("failed to build status patch: %w", err)
+	}
+
+	log.Info("Patching HCP status with new configuration and version status")
+	if err := h.mgtClusterClient.Status().Patch(ctx, hcp,
+		crclient.RawPatch(types.JSONPatchType, patch)); err != nil {
+		return reconcile.Result{}, fmt.Errorf("failed to patch hcp status: %w", err)
 	}
+	log.Info("Successfully patched HCP status")
 
 	return reconcile.Result{}, nil
 }
 
+type jsonPatchOp struct {
+	Op    string      `json:"op"`
+	Path  string      `json:"path"`
+	Value interface{} `json:"value,omitempty"`
+}
+
+func buildStatusPatch(original, modified *hyperv1.HostedControlPlane) ([]byte, error) {
+	origJSON, err := json.Marshal(original.Status)
+	if err != nil {
+		return nil, err
+	}
+	modJSON, err := json.Marshal(modified.Status)
+	if err != nil {
+		return nil, err
+	}
+
+	var origMap, modMap map[string]json.RawMessage
+	if err := json.Unmarshal(origJSON, &origMap); err != nil {
+		return nil, err
+	}
+	if err := json.Unmarshal(modJSON, &modMap); err != nil {
+		return nil, err
+	}
+
+	// Optimistic lock: fail if the object was modified since our read.
+	ops := []jsonPatchOp{{Op: "test", Path: "/metadata/resourceVersion", Value: original.ResourceVersion}}
+
+	for key, modVal := range modMap {
+		origVal, exists := origMap[key]
+		if !exists {
+			ops = append(ops, jsonPatchOp{Op: "add", Path: "/status/" + key, Value: modVal})
+		} else if !bytes.Equal(origVal, modVal) {
+			ops = append(ops, jsonPatchOp{Op: "replace", Path: "/status/" + key, Value: modVal})
+		}
+	}
+	for key := range origMap {
+		if _, exists := modMap[key]; !exists {
+			ops = append(ops, jsonPatchOp{Op: "remove", Path: "/status/" + key})
+		}
+	}
+
+	return json.Marshal(ops)
+}
+
 // findClusterOperatorStatusCondition is identical to meta.FindStatusCondition except that it works on config1.ClusterOperatorStatusCondition instead of
 // metav1.StatusCondition
 func findClusterOperatorStatusCondition(conditions []configv1.ClusterOperatorStatusCondition, conditionType configv1.ClusterStatusConditionType) *configv1.ClusterOperatorStatusCondition {