From a56c8bcc586a59ef67b75719c6a71194e4ca9c82 Mon Sep 17 00:00:00 2001
From: Philipp Hossner <philipp.hossner@posteo.de>
Date: Fri, 20 Dec 2024 11:25:17 +0000
Subject: [PATCH] MAJOR: kubernetes-ingress: Support to specify HPA behavior

Signed-off-by: Philipp Hossner <philipp.hossner@posteo.de>
---
 kubernetes-ingress/ci/deployment-hpa-values.yaml | 12 ++++++++++++
 kubernetes-ingress/templates/controller-hpa.yaml |  3 +++
 kubernetes-ingress/values.yaml                   |  6 ++++++
 3 files changed, 21 insertions(+)

diff --git a/kubernetes-ingress/ci/deployment-hpa-values.yaml b/kubernetes-ingress/ci/deployment-hpa-values.yaml
index f3a5701..f5da547 100644
--- a/kubernetes-ingress/ci/deployment-hpa-values.yaml
+++ b/kubernetes-ingress/ci/deployment-hpa-values.yaml
@@ -4,6 +4,18 @@ controller:
     minReplicas: 1
     maxReplicas: 5
     targetCPUUtilizationPercentage: 80
+    behavior:
+      scaleUp:
+        policies:
+          - type: Percent
+            value: 900
+            periodSeconds: 60
+      scaleDown:
+        stabilizationWindowSeconds: 600
+        policies:
+          - type: Pods
+            value: 1
+            periodSeconds: 600
 
 defaultBackend:
   autoscaling:
diff --git a/kubernetes-ingress/templates/controller-hpa.yaml b/kubernetes-ingress/templates/controller-hpa.yaml
index 3f596c0..27772df 100644
--- a/kubernetes-ingress/templates/controller-hpa.yaml
+++ b/kubernetes-ingress/templates/controller-hpa.yaml
@@ -44,6 +44,9 @@ spec:
     name: {{ include "kubernetes-ingress.fullname" . }}
   minReplicas: {{ .Values.controller.autoscaling.minReplicas }}
   maxReplicas: {{ .Values.controller.autoscaling.maxReplicas }}
+  {{- if .Values.controller.autoscaling.behavior }}
+  behavior: {{- toYaml .Values.controller.autoscaling.behavior | nindent 4 }}
+  {{- end }}
   metrics:
   {{- if .Values.controller.autoscaling.targetCPUUtilizationPercentage }}
     - type: Resource
diff --git a/kubernetes-ingress/values.yaml b/kubernetes-ingress/values.yaml
index 436ffec..b2170dc 100644
--- a/kubernetes-ingress/values.yaml
+++ b/kubernetes-ingress/values.yaml
@@ -235,6 +235,12 @@ controller:
     annotations: {}
     #  annotationKey: value
 
+    ## Behavior
+    ## ref: https://kubernetes.io/docs/tasks/run-application/horizontal-pod-autoscale/#configurable-scaling-behavior
+    # behavior:
+    #   scaleDown:
+    #      stabilizationWindowSeconds: 3600
+
     ## Custom metrics (example)
     ## ref: https://kubernetes.io/docs/tasks/run-application/horizontal-pod-autoscale-walkthrough/#autoscaling-on-multiple-metrics-and-custom-metrics
     # custom: