[stable/nginx-ingress] add HPA in case of Deployment (#2736)

stable/nginx-ingress/Chart.yaml

@@ -1,5 +1,5 @@
 name: nginx-ingress
-version: 0.8.15
+version: 0.8.16
 appVersion: 0.9.0-beta.15
 description: An nginx Ingress controller that uses ConfigMap to store the nginx configuration.
 icon: https://upload.wikimedia.org/wikipedia/commons/thumb/c/c5/Nginx_logo.svg/500px-Nginx_logo.svg.png

stable/nginx-ingress/templates/controller-hpa.yaml

@@ -0,0 +1,26 @@
+{{- if eq .Values.controller.kind "Deployment" }}
+{{- if .Values.controller.autoscaling.enabled }}
+apiVersion: autoscaling/v2beta1
+kind: HorizontalPodAutoscaler
+metadata:
+  labels:
+    app: {{ template "name" . }}
+    chart: {{ .Chart.Name }}-{{ .Chart.Version }}
+    component: "{{ .Values.controller.name }}"
+    heritage: {{ .Release.Service }}
+    release: {{ .Release.Name }}
+  name: {{ template "controller.fullname" . }}
+spec:
+  scaleTargetRef:
+    apiVersion: apps/v1beta1
+    kind: Deployment
+    name:  {{ template "controller.fullname" . }}
+  minReplicas: "{{ .Values.controller.autoscaling.minReplicas }}"
+  maxReplicas: "{{ .Values.controller.autoscaling.maxReplicas }}"
+  metrics:
+  - type: Resource
+    resource:
+      name: cpu
+      targetAverageUtilization: "{{ .Values.controller.autoscaling.targetAverageUtilization }}"
+{{- end }}
+{{- end }}

stable/nginx-ingress/values.yaml

@@ -97,6 +97,12 @@ controller:
   #    cpu: 100m
   #    memory: 64Mi
 
+  autoscaling:
+    enabled: false
+  #  minReplicas: 1
+  #  maxReplicas: 11
+  #  targetAverageUtilization: 50
+
   ## Override NGINX template
   customTemplate:
     configMapName: ""