contrib/kube-prometheus: Add sample-app for showing custom metrics with HPA

Use interval in ServiceMonitor endpoint

Reintroduce updated dpeloy.sh & teardown.sh

experimental/custom-metrics-api/sample-app.yaml

@@ -0,0 +1,67 @@
+kind: ServiceMonitor
+apiVersion: monitoring.coreos.com/v1
+metadata:
+  name: sample-app
+  labels:
+    app: sample-app
+spec:
+  selector:
+    matchLabels:
+      app: sample-app
+  endpoints: 
+  - port: http
+    interval: 5s
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: sample-app
+  labels:
+    app: sample-app
+spec:
+  ports:
+  - name: http
+    port: 8080
+    targetPort: 8080
+  selector:
+    app: sample-app
+---
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: sample-app
+  labels:
+    app: sample-app
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: sample-app
+  template:
+    metadata:
+      labels:
+        app: sample-app
+    spec:
+      containers:
+      - image: luxas/autoscale-demo:v0.1.2
+        name: metrics-provider
+        ports:
+        - name: http
+          containerPort: 8080
+---
+kind: HorizontalPodAutoscaler
+apiVersion: autoscaling/v2beta1
+metadata:
+  name: sample-app
+spec:
+  scaleTargetRef:
+    apiVersion: apps/v1
+    kind: Deployment
+    name: sample-app
+  minReplicas: 1
+  maxReplicas: 10
+  metrics:
+  - type: Pods
+    pods:
+      metricName: http_requests
+      targetAverageValue: 500m