From b887b70d809e085fb06fb46cc7f9d6ecaa850fc1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alby=20Hern=C3=A1ndez?= <donfumero@gmail.com>
Date: Wed, 11 Sep 2024 09:01:16 +0100
Subject: [PATCH] feat: Add autoscaling and PDB templates to Helm chart

---
 charts/doorkeeper/Chart.yaml         |  2 +-
 charts/doorkeeper/templates/hpa.yaml | 62 ++++++++++++++++++++++++++++
 charts/doorkeeper/templates/pdb.yaml | 35 ++++++++++++++++
 charts/doorkeeper/values.yaml        | 22 ++++++++++
 4 files changed, 120 insertions(+), 1 deletion(-)
 create mode 100644 charts/doorkeeper/templates/hpa.yaml
 create mode 100644 charts/doorkeeper/templates/pdb.yaml

diff --git a/charts/doorkeeper/Chart.yaml b/charts/doorkeeper/Chart.yaml
index 1e553dd..aaedbf4 100644
--- a/charts/doorkeeper/Chart.yaml
+++ b/charts/doorkeeper/Chart.yaml
@@ -4,7 +4,7 @@ type: application
 description: >-
   A Helm chart for Doorkeeper, a tiny HTTP server to be used as 
   external authentication service for Envoy 
-version: &chartVersion 0.1.6
+version: &chartVersion 0.2.0
 appVersion: *chartVersion
 kubeVersion: ">=1.22.0-0"
 home: https://github.com/freepik-company/doorkeeper
diff --git a/charts/doorkeeper/templates/hpa.yaml b/charts/doorkeeper/templates/hpa.yaml
new file mode 100644
index 0000000..07cdad0
--- /dev/null
+++ b/charts/doorkeeper/templates/hpa.yaml
@@ -0,0 +1,62 @@
+{{- if .Values.server.autoscaling }}
+apiVersion: autoscaling/v2
+kind: HorizontalPodAutoscaler
+metadata:
+  name: {{ include "doorkeeper.fullname" . }}
+  labels:
+    {{- include "doorkeeper.labels" . | nindent 4 }}
+    {{- with .Values.server.extraLabels }}
+    {{- toYaml . | nindent 4 }}
+    {{- end }}
+
+  {{- with .Values.server.autoscaling.annotations }}
+  annotations:
+    {{- toYaml . | nindent 4 }}
+  {{- end }}
+  
+spec:
+  {{- if .Values.server.autoscaling.behavior }}
+  behavior:
+    {{- toYaml .Values.server.autoscaling.behavior | nindent 4 }}
+  {{- end }}
+
+  # Match the generated Deployment by reference
+  scaleTargetRef:
+    apiVersion: apps/v1
+    kind: Deployment
+    name: {{ include "doorkeeper.fullname" . }}
+
+  {{- with .Values.server.autoscaling }}
+  minReplicas: {{ .minReplicas }}
+  maxReplicas: {{ .maxReplicas }}
+
+  metrics:
+    # Changing the order of the metrics will cause ArgoCD
+    # to go into a sync loop memory needs to be first.
+    # More info in: https://github.com/argoproj/argo-cd/issues/1079
+    {{- with .targetMemoryUtilizationPercentage }}
+    - type: Resource
+      resource:
+        name: memory
+        target:
+          type: Utilization
+          averageUtilization: {{ . }}
+    {{- end }}
+
+    {{- with .targetCPUUtilizationPercentage }}
+    - type: Resource
+      resource:
+        name: cpu
+        target:
+          type: Utilization
+          averageUtilization: {{ . }}
+    {{- end }}
+
+    {{- if .customRules -}}
+      {{- toYaml .customRules | nindent 4}}
+    {{- end }}
+
+  {{- end }}
+
+---
+{{- end }}
diff --git a/charts/doorkeeper/templates/pdb.yaml b/charts/doorkeeper/templates/pdb.yaml
new file mode 100644
index 0000000..1fd382d
--- /dev/null
+++ b/charts/doorkeeper/templates/pdb.yaml
@@ -0,0 +1,35 @@
+
+{{- if .Values.server.disruption }}
+apiVersion: policy/v1
+kind: PodDisruptionBudget
+metadata:
+  name: {{ include "doorkeeper.fullname" . }}
+  labels:
+    {{- include "doorkeeper.labels" . | nindent 4 }}
+    {{- with .Values.server.extraLabels }}
+    {{- toYaml . | nindent 4 }}
+    {{- end }}
+
+  {{- with .Values.server.disruption.annotations }}
+  annotations:
+    {{- toYaml . | nindent 4 }}
+  {{- end }}
+
+
+spec:
+  {{- with .Values.server.disruption.minAvailable }}
+  minAvailable: {{ . }}
+  {{- end }}
+
+  {{- with .Values.server.disruption.maxUnavailable }}
+  maxUnavailable: {{ . }}
+  {{- end }}
+
+  selector:
+    matchLabels:
+      {{- include "doorkeeper.selectorLabels" . | nindent 4 }}
+      {{- with .Values.server.extraLabels }}
+      {{- toYaml . | nindent 8 }}
+      {{- end }}
+---
+{{- end }}
diff --git a/charts/doorkeeper/values.yaml b/charts/doorkeeper/values.yaml
index 43339c9..3299b92 100644
--- a/charts/doorkeeper/values.yaml
+++ b/charts/doorkeeper/values.yaml
@@ -141,6 +141,28 @@ server:
 
   affinity: {}
 
+  # Pod Disruption Budget configurations
+  disruption:
+    annotations: {}
+    minAvailable: 2
+    #maxUnavailable: 1
+
+  # Horizontal Pod Autoscaling configurations
+  autoscaling:
+    annotations: {}
+    minReplicas: 1
+    maxReplicas: 5
+
+    targetCPUUtilizationPercentage: 80
+    # targetMemoryUtilizationPercentage: 80
+
+    ## see https://kubernetes.io/docs/tasks/run-application/horizontal-pod-autoscale-walkthrough/#autoscaling-on-multiple-metrics-and-custom-metrics
+    customRules: []
+
+    ## see https://kubernetes.io/docs/tasks/run-application/horizontal-pod-autoscale/#support-for-configurable-scaling-behavior
+    behavior: {}
+
+
 # Define some extra resources to be created
 # This section is useful when you need ExternalResource or Secrets, etc.
 extraResources: []