chore: add scale-to-zero overlay

deploy/overlays/production-scale-to-zero/external-service.yaml

@@ -0,0 +1,14 @@
+apiVersion: v1
+kind: Service
+metadata:
+  creationTimestamp: null
+  labels:
+    app: keda-add-ons-http-interceptor-proxy
+  name: keda-add-ons-http-interceptor-proxy
+spec:
+  externalName: keda-add-ons-http-interceptor-proxy.keda
+  selector:
+    app: keda-add-ons-http-interceptor-proxy
+  type: ExternalName
+status:
+  loadBalancer: {}

deploy/overlays/production-scale-to-zero/http-scaled-object.yaml

@@ -0,0 +1,24 @@
+kind: HTTPScaledObject
+apiVersion: http.keda.sh/v1alpha1
+metadata:
+  name: math-exercises
+spec:
+  hosts:
+    - "math-tables.cl1.parano.ch"
+  pathPrefixes:
+    - /
+  scaleTargetRef:
+    name: math-exercises-app
+    kind: Deployment
+    apiVersion: apps/v1
+    service: math-exercises-service
+    portName: http
+  replicas:
+    min: 0
+    max: 3
+  scaledownPeriod: 60
+  scalingMetric:
+    requestRate:
+      granularity: 1s
+      targetValue: 100
+      window: 1m

deploy/overlays/production-scale-to-zero/kustomization.yaml

@@ -0,0 +1,39 @@
+apiVersion: kustomize.config.k8s.io/v1beta1
+kind: Kustomization
+namespace: math-tables
+resources:
+- ../production
+- external-service.yaml
+- http-scaled-object.yaml
+patches:
+- patch: |
+    [
+      {
+        "op": "remove",
+        "path": "/spec/replicas"
+      }
+    ]
+  target:
+    group: apps
+    version: v1
+    kind: Deployment
+    name: math-exercises-app
+- path: remove-pdb.yaml
+- patch: |
+    [
+      {
+        "op": "replace",
+        "path": "/spec/rules/0/http/paths/0/backend/service/port/number",
+        "value": 8080
+      },
+      {
+        "op": "replace",
+        "path": "/spec/rules/0/http/paths/0/backend/service/name",
+        "value": "keda-add-ons-http-interceptor-proxy"
+      }
+    ]
+  target:
+    group: networking.k8s.io
+    version: v1
+    kind: Ingress
+    name: math-exercises-ingress

deploy/overlays/production-scale-to-zero/remove-pdb.yaml

@@ -0,0 +1,5 @@
+apiVersion: policy/v1
+kind: PodDisruptionBudget
+metadata:
+  name: math-exercises-pdb
+$patch: delete