Prevent unnecessary ephemeral runner recreations

api/v1alpha1/horizontalrunnerautoscaler_types.go

@@ -107,6 +107,9 @@ type CapacityReservation struct {
 	Name           string      `json:"name,omitempty"`
 	ExpirationTime metav1.Time `json:"expirationTime,omitempty"`
 	Replicas       int         `json:"replicas,omitempty"`
+
+	// +optional
+	EffectiveTime metav1.Time `json:"effectiveTime,omitempty"`
 }
 
 type ScaleTargetRef struct {

api/v1alpha1/runnerdeployment_types.go

@@ -31,6 +31,14 @@ type RunnerDeploymentSpec struct {
 	// +nullable
 	Replicas *int `json:"replicas,omitempty"`
 
+	// EffectiveTime is the time the upstream controller requested to sync Replicas.
+	// It is usually populated by the webhook-based autoscaler via HRA.
+	// The value is inherited to RunnerRepicaSet(s) and used to prevent ephemeral runners from unnecessarily recreated.
+	//
+	// +optional
+	// +nullable
+	EffectiveTime *metav1.Time `json:"effectiveTime"`
+
 	// +optional
 	// +nullable
 	Selector *metav1.LabelSelector `json:"selector"`

api/v1alpha1/runnerreplicaset_types.go

@@ -26,6 +26,15 @@ type RunnerReplicaSetSpec struct {
 	// +nullable
 	Replicas *int `json:"replicas,omitempty"`
 
+	// EffectiveTime is the time the upstream controller requested to sync Replicas.
+	// It is usually populated by the webhook-based autoscaler via HRA and RunnerDeployment.
+	// The value is used to prevent runnerreplicaset controller from unnecessarily recreating ephemeral runners
+	// based on potentially outdated Replicas value.
+	//
+	// +optional
+	// +nullable
+	EffectiveTime *metav1.Time `json:"effectiveTime"`
+
 	// +optional
 	// +nullable
 	Selector *metav1.LabelSelector `json:"selector"`

api/v1alpha1/zz_generated.deepcopy.go

@@ -47,6 +47,7 @@ func (in *CacheEntry) DeepCopy() *CacheEntry {
 func (in *CapacityReservation) DeepCopyInto(out *CapacityReservation) {
 	*out = *in
 	in.ExpirationTime.DeepCopyInto(&out.ExpirationTime)
+	in.EffectiveTime.DeepCopyInto(&out.EffectiveTime)
 }
 
 // DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new CapacityReservation.
@@ -498,6 +499,10 @@ func (in *RunnerDeploymentSpec) DeepCopyInto(out *RunnerDeploymentSpec) {
 		*out = new(int)
 		**out = **in
 	}
+	if in.EffectiveTime != nil {
+		in, out := &in.EffectiveTime, &out.EffectiveTime
+		*out = (*in).DeepCopy()
+	}
 	if in.Selector != nil {
 		in, out := &in.Selector, &out.Selector
 		*out = new(metav1.LabelSelector)
@@ -812,6 +817,10 @@ func (in *RunnerReplicaSetSpec) DeepCopyInto(out *RunnerReplicaSetSpec) {
 		*out = new(int)
 		**out = **in
 	}
+	if in.EffectiveTime != nil {
+		in, out := &in.EffectiveTime, &out.EffectiveTime
+		*out = (*in).DeepCopy()
+	}
 	if in.Selector != nil {
 		in, out := &in.Selector, &out.Selector
 		*out = new(metav1.LabelSelector)