feat: add HPA scaling based on memory to web service (#46)

techfromsage · Aug 31, 2022 · 07c7ee1 · 07c7ee1
1 parent cafb145
commit 07c7ee1
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Showing 4 changed files with 459 additions and 13 deletions.
diff --git a/lib/web-service/web-service-props.ts b/lib/web-service/web-service-props.ts
@@ -12,7 +12,10 @@ export interface HorizontalPodAutoscalerProps {
   readonly maxReplicas: number;
 
   /** Target average CPU utilization, as a percentage of the request. */
-  readonly cpuTargetUtilization: number;
+  readonly cpuTargetUtilization?: number;
+
+  /** Target average memory utilization, as a percentage of the request. */
+  readonly memoryTargetUtilization?: number;
 }
 
 export interface NginxContainerProps {

diff --git a/lib/web-service/web-service.ts b/lib/web-service/web-service.ts
@@ -7,6 +7,7 @@ import {
   KubeHorizontalPodAutoscalerV2Beta2,
   KubeIngress,
   KubeService,
+  MetricSpecV2Beta2,
   Quantity,
   Volume,
 } from "../../imports/k8s";
@@ -282,6 +283,18 @@ export class WebService extends Construct {
         "Release stage must be specified when canary deployments are enabled"
       );
     }
+
+    if (
+      props.horizontalPodAutoscaler &&
+      !(
+        props.horizontalPodAutoscaler.cpuTargetUtilization ||
+        props.horizontalPodAutoscaler.memoryTargetUtilization
+      )
+    ) {
+      throw new Error(
+        "Either cpuTargetUtilization or memoryTargetUtilization must be specified to use a horizontalPodAutoscaler"
+      );
+    }
   }
 
   findPorts(props: WebServiceProps): {
@@ -388,6 +401,34 @@ export class WebService extends Construct {
     props: HorizontalPodAutoscalerProps,
     labels: { [key: string]: string }
   ): void {
+    const metrics: Array<MetricSpecV2Beta2> = [];
+
+    if (props.cpuTargetUtilization) {
+      metrics.push({
+        type: "Resource",
+        resource: {
+          name: "cpu",
+          target: {
+            type: "Utilization",
+            averageUtilization: props.cpuTargetUtilization,
+          },
+        },
+      });
+    }
+
+    if (props.memoryTargetUtilization) {
+      metrics.push({
+        type: "Resource",
+        resource: {
+          name: "memory",
+          target: {
+            type: "Utilization",
+            averageUtilization: props.memoryTargetUtilization,
+          },
+        },
+      });
+    }
+
     new KubeHorizontalPodAutoscalerV2Beta2(this, `${deployment.node.id}-hpa`, {
       metadata: {
         labels,
@@ -400,18 +441,7 @@ export class WebService extends Construct {
         },
         minReplicas: props.minReplicas,
         maxReplicas: props.maxReplicas,
-        metrics: [
-          {
-            type: "Resource",
-            resource: {
-              name: "cpu",
-              target: {
-                type: "Utilization",
-                averageUtilization: props.cpuTargetUtilization,
-              },
-            },
-          },
-        ],
+        metrics: metrics,
       },
     });
   }