Make VitessCell scalable by HPA

Signed-off-by: Sina Siadat <[email protected]>
planetscale · Aug 30, 2024 · 718d930 · 718d930
1 parent 224d6c1
commit 718d930
Show file tree

Hide file tree

Showing 4 changed files with 48 additions and 0 deletions.
diff --git a/deploy/crds/planetscale.com_vitesscells.yaml b/deploy/crds/planetscale.com_vitesscells.yaml
@@ -738,6 +738,12 @@ spec:
                 properties:
                   available:
                     type: string
+                  labelSelector:
+                    type: string
+                  replicas:
+                    format: int32
+                    minimum: 0
+                    type: integer
                   serviceName:
                     type: string
                 type: object
@@ -768,4 +774,8 @@ spec:
     served: true
     storage: true
     subresources:
+      scale:
+        labelSelectorPath: .status.gateway.labelSelector
+        specReplicasPath: .spec.gateway.replicas
+        statusReplicasPath: .status.gateway.replicas
       status: {}
diff --git a/docs/api/index.html b/docs/api/index.html
@@ -3614,6 +3614,30 @@ <h3 id="planetscale.com/v2.VitessCellGatewayStatus">VitessCellGatewayStatus
 <p>ServiceName is the name of the Service for this cell&rsquo;s vtgate.</p>
 </td>
 </tr>
+<tr>
+<td>
+<code>labelSelector</code></br>
+<em>
+string
+</em>
+</td>
+<td>
+<p>LabelSelector is required by the Scale subresource, which is used by
+HorizontalPodAutoscaler when reading pod metrics.</p>
+</td>
+</tr>
+<tr>
+<td>
+<code>replicas</code></br>
+<em>
+int32
+</em>
+</td>
+<td>
+<p>Replicas is required by the Scale subresource, which is used by
+HorizontalPodAutoscaler to determine the current number of replicas.</p>
+</td>
+</tr>
 </tbody>
 </table>
 <h3 id="planetscale.com/v2.VitessCellImages">VitessCellImages

diff --git a/pkg/apis/planetscale/v2/vitesscell_types.go b/pkg/apis/planetscale/v2/vitesscell_types.go
@@ -39,6 +39,7 @@ import (
 // just like a Deployment can manage Pods that run on multiple Nodes.
 // +kubebuilder:resource:path=vitesscells,shortName=vtc
 // +kubebuilder:subresource:status
+// +kubebuilder:subresource:scale:specpath=.spec.gateway.replicas,statuspath=.status.gateway.replicas,selectorpath=.status.gateway.labelSelector
 type VitessCell struct {
 	metav1.TypeMeta   `json:",inline"`
 	metav1.ObjectMeta `json:"metadata,omitempty"`
@@ -252,6 +253,13 @@ type VitessCellGatewayStatus struct {
 	Available corev1.ConditionStatus `json:"available,omitempty"`
 	// ServiceName is the name of the Service for this cell's vtgate.
 	ServiceName string `json:"serviceName,omitempty"`
+	// LabelSelector is required by the Scale subresource, which is used by
+	// HorizontalPodAutoscaler when reading pod metrics.
+	LabelSelector string `json:"labelSelector,omitempty"`
+	// Replicas is required by the Scale subresource, which is used by
+	// HorizontalPodAutoscaler to determine the current number of replicas.
+	// +kubebuilder:validation:Minimum=0
+	Replicas int32 `json:"replicas,omitempty"`
 }
 
 // VitessCellStatus defines the observed state of VitessCell

diff --git a/pkg/controller/vitesscell/reconcile_vtgate.go b/pkg/controller/vitesscell/reconcile_vtgate.go
@@ -161,6 +161,12 @@ func (r *ReconcileVitessCell) reconcileVtgate(ctx context.Context, vtc *planetsc
 			curObj := obj.(*appsv1.Deployment)
 
 			status := &vtc.Status.Gateway
+			if replicas :=curObj.Spec.Replicas; replicas != nil {
+				status.Replicas = *replicas
+			}
+			if selector := curObj.Spec.Selector; selector != nil {
+				status.LabelSelector = selector.String()
+			}
 			if available := conditions.Deployment(curObj.Status.Conditions, appsv1.DeploymentAvailable); available != nil {
 				status.Available = available.Status
 			}