Scaling based on custom metrics

CHANGELOG.md

@@ -7,6 +7,10 @@ and this project's packages adheres to [Semantic Versioning](http://semver.org/s
 
 ## [Unreleased]
 
+### Added
+
+- Add scaling based on custom metrics ([#209](https://github.com/giantswarm/coredns-app/pull/209)).
+
 ## [1.16.0] - 2023-05-04
 
 ### Changed

helm/coredns-app/templates/hpa.yaml

@@ -1,3 +1,4 @@
+{{- if .Values.hpa.enabled }}
 apiVersion: {{ ternary "autoscaling/v2" "autoscaling/v2beta2" (.Capabilities.APIVersions.Has "autoscaling/v2") }}
 kind: HorizontalPodAutoscaler
 metadata:
@@ -12,23 +13,27 @@ spec:
     kind: Deployment
     name: coredns-workers
   metrics:
-  {{- with .Values.hpa.targetMemoryUtilizationPercentage }}
-  - type: Resource
-    resource:
-      name: memory
-      target:
-        type: Utilization
-        averageUtilization: {{ . }}
-  {{- end }}
-  {{- with .Values.hpa.targetCPUUtilizationPercentage }}
-  - type: Resource
-    resource:
-      name: cpu
-      target:
-        type: Utilization
-        averageUtilization: {{ . }}
-  {{- end }}
+    {{- with .Values.hpa.metrics }}
+    {{- toYaml . | nindent 4 }}
+    {{- end }}
+    {{- with .Values.hpa.targetMemoryUtilizationPercentage }}
+    - type: Resource
+      resource:
+        name: memory
+        target:
+          type: Utilization
+          averageUtilization: {{ . }}
+    {{- end }}
+    {{- with .Values.hpa.targetCPUUtilizationPercentage }}
+    - type: Resource
+      resource:
+        name: cpu
+        target:
+          type: Utilization
+          averageUtilization: {{ . }}
+    {{- end }}
   {{- with .Values.hpa.behavior }}
   behavior:
     {{- toYaml . | nindent 4 }}
   {{- end }}
+{{- end }}

helm/coredns-app/values.schema.json

@@ -72,9 +72,15 @@
                         }
                     }
                 },
+                "enabled": {
+                    "type": "boolean"
+                },
                 "maxReplicas": {
                     "type": "integer"
                 },
+                "metrics": {
+                    "type": "array"
+                },
                 "minReplicas": {
                     "type": "integer"
                 },

helm/coredns-app/values.yaml

@@ -10,10 +10,12 @@ userID: 33
 groupID: 33
 
 hpa:
+  enabled: true
   minReplicas: 2
   maxReplicas: 50
   targetCPUUtilizationPercentage: 70
   targetMemoryUtilizationPercentage: 80
+  metrics: []
   # The stabilization window is used to restrict the flapping of replica count
   # when the metrics used for scaling keep fluctuating.
   # This is very useful for large scale clusters to prevent the CoreDNS from flapping