Code Review for status.desiredReplicas

Author: nowjean

charts/nginx-gateway-fabric/README.md

@@ -278,7 +278,7 @@ The following table lists the configurable parameters of the NGINX Gateway Fabri
 | `nginx.kind` | The kind of NGINX deployment. | string | `"deployment"` |
 | `nginx.plus` | Is NGINX Plus image being used. | bool | `false` |
 | `nginx.pod` | The pod configuration for the NGINX data plane pod. This is applied globally to all Gateways managed by this instance of NGINX Gateway Fabric. | object | `{}` |
-| `nginx.replicas` | The number of replicas of the NGINX Deployment. | int | `1` |
+| `nginx.replicas` | The number of replicas of the NGINX Deployment. This value is ignored if autoscaling.enabled is true. | int | `1` |
 | `nginx.service` | The service configuration for the NGINX data plane. This is applied globally to all Gateways managed by this instance of NGINX Gateway Fabric. | object | `{"externalTrafficPolicy":"Local","loadBalancerClass":"","loadBalancerIP":"","loadBalancerSourceRanges":[],"nodePorts":[],"type":"LoadBalancer"}` |
 | `nginx.service.externalTrafficPolicy` | The externalTrafficPolicy of the service. The value Local preserves the client source IP. | string | `"Local"` |
 | `nginx.service.loadBalancerClass` | LoadBalancerClass is the class of the load balancer implementation this Service belongs to. Requires nginx.service.type set to LoadBalancer. | string | `""` |
@@ -319,7 +319,7 @@ The following table lists the configurable parameters of the NGINX Gateway Fabri
 | `nginxGateway.readinessProbe.enable` | Enable the /readyz endpoint on the control plane. | bool | `true` |
 | `nginxGateway.readinessProbe.initialDelaySeconds` | The number of seconds after the Pod has started before the readiness probes are initiated. | int | `3` |
 | `nginxGateway.readinessProbe.port` | Port in which the readiness endpoint is exposed. | int | `8081` |
-| `nginxGateway.replicas` | The number of replicas of the NGINX Gateway Fabric Deployment. | int | `1` |
+| `nginxGateway.replicas` | The number of replicas of the NGINX Gateway Fabric Deployment. This value is ignored if autoscaling.enabled is true. | int | `1` |
 | `nginxGateway.resources` | The resource requests and/or limits of the nginx-gateway container. | object | `{}` |
 | `nginxGateway.service` | The service configuration for the NGINX Gateway Fabric control plane. | object | `{"annotations":{},"labels":{}}` |
 | `nginxGateway.service.annotations` | The annotations of the NGINX Gateway Fabric control plane service. | object | `{}` |

charts/nginx-gateway-fabric/values.schema.json

@@ -478,7 +478,7 @@
         },
         "replicas": {
           "default": 1,
-          "description": "The number of replicas of the NGINX Deployment.",
+          "description": "The number of replicas of the NGINX Deployment. This value is ignored if autoscaling.enabled is true.",
           "required": [],
           "title": "replicas",
           "type": "integer"
@@ -897,7 +897,7 @@
         },
         "replicas": {
           "default": 1,
-          "description": "The number of replicas of the NGINX Gateway Fabric Deployment.",
+          "description": "The number of replicas of the NGINX Gateway Fabric Deployment. This value is ignored if autoscaling.enabled is true.",
           "required": [],
           "title": "replicas",
           "type": "integer"

charts/nginx-gateway-fabric/values.yaml

@@ -80,7 +80,7 @@ nginxGateway:
     # Secrets must exist in the same namespace as the helm release.
     imagePullSecrets: []
 
-  # -- The number of replicas of the NGINX Gateway Fabric Deployment.
+  # -- The number of replicas of the NGINX Gateway Fabric Deployment. This value is ignored if autoscaling.enabled is true.
   replicas: 1
 
   # The configuration for leader election.
@@ -226,7 +226,7 @@ nginx:
   # -- The kind of NGINX deployment.
   kind: deployment
 
-  # -- The number of replicas of the NGINX Deployment.
+  # -- The number of replicas of the NGINX Deployment. This value is ignored if autoscaling.enabled is true.
   replicas: 1
 
   autoscaling:

internal/controller/provisioner/objects.go

@@ -615,7 +615,24 @@ func (p *NginxProvisioner) buildNginxDeployment(
 	}
 
 	if deploymentCfg.Replicas != nil {
-		deployment.Spec.Replicas = deploymentCfg.Replicas
+		replicas := deploymentCfg.Replicas
+
+		if isAutoscalingEnabled(&deploymentCfg) {
+			ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+			defer cancel()
+
+			hpa := &autoscalingv2.HorizontalPodAutoscaler{}
+			err := p.k8sClient.Get(ctx, types.NamespacedName{
+				Namespace: objectMeta.Namespace,
+				Name:      objectMeta.Name,
+			}, hpa)
+			if err == nil && hpa.Status.DesiredReplicas > 0 {
+				// overwrite with HPA's desiredReplicas
+				replicas = helpers.GetPointer(hpa.Status.DesiredReplicas)
+			}
+		}
+
+		deployment.Spec.Replicas = replicas
 	}
 
 	return deployment, nil