Exposing scale subresource to enable HPA's to modify the replicas of Infinispan CR

api/v1/infinispan_types.go

@@ -611,6 +611,9 @@ type InfinispanStatus struct {
 	// +optional
 	// +operator-sdk:csv:customresourcedefinitions:type=status,displayName="Operator Status"
 	Operator Operator `json:"operator,omitempty"`
+	// The Selector used to identify Infinispan cluster pods
+	// +optional
+	Selector string  `json:"selector"`
 }
 
 type OperandPhase string
@@ -663,6 +666,7 @@ type Operator struct {
 
 // +kubebuilder:object:root=true
 // +kubebuilder:subresource:status
+// +kubebuilder:subresource:scale:specpath=.spec.replicas,statuspath=.status.replicas,selectorpath=.status.selector
 // +operator-sdk:csv:customresourcedefinitions:displayName="Infinispan Cluster"
 
 // Infinispan is the Schema for the infinispans API

config/crd/bases/infinispan.org_infinispans.yaml

@@ -2457,11 +2457,18 @@ spec:
                     description: The secret that contains user credentials.
                     type: string
                 type: object
+              selector:
+                description: The Operator Selector
+                type: string
               statefulSetName:
                 type: string
             type: object
         type: object
     served: true
     storage: true
     subresources:
+      scale:
+        labelSelectorPath: .status.selector
+        specReplicasPath: .spec.replicas
+        statusReplicasPath: .status.replicas
       status: {}

pkg/reconcile/pipeline/infinispan/handler/provision/statefulsets.go

@@ -60,9 +60,16 @@ func ClusterStatefulSet(i *ispnv1.Infinispan, ctx pipeline.Context) {
 		return
 	}
 
+	selector, err := metav1.LabelSelectorAsSelector(statefulSet.Spec.Selector)
+
+	if err != nil {
+		ctx.Requeue(fmt.Errorf("error retrieving StatefulSet labels: %w", err))
+		return
+	}
 	_ = ctx.UpdateInfinispan(func() {
 		i.Status.Replicas = &i.Spec.Replicas
 		i.Status.StatefulSetName = statefulSet.Name
+		i.Status.Selector = selector.String()
 	})
 }