deltasquare4 / k8s-http-autoscaling-demo

A demo that shows http-req-count-based autoscaling on Kubernetes (minikube)

HorizontalPodAutoscaler HTTP Server Demo

This demo application demonstrates use of Kubernetes' HorizontalPodAutoscaler to scale HTTP servers based on requests-per-second metric tracked using Prometheus.

Prerequisites

• Docker
• Minikube with driver none: minikube start --vm-driver none
  • metrics-server and heapster addons enabled on minikube: minikube addons enable <addon>
• Prometheus deployed on the minikue cluster

Installation and Configuration

# Build container image locally
docker build -t server .

# Configure minikube on local docker (linux)
minikube start --vm-driver none

# Add plugins to minikube
minikube addons enable heapster metrics-server

# Setting Up Minikube
# Add the following argument to controller manager to reduce delay
--horizontal-pod-autoscaler-downscale-delay=30s

# Deploy the prometheus and prometheus adapter
kubectl apply -f k8s/prometheus
kubectl apply -f k8s/prom-adapter
kubectl apply -f k8s/servicemonitor.yaml

# Depoy the application
kubectl apply -f k8s/deployment.yaml
kubectl apply -f k8s/service.yaml

# Get URL to the application
minikube service prom-demo --url

# Generate load on the application using Apache Bench
ab -n 100000 -c 20 $(minikube service prom-demo --url)/

# Install/configure HPA
kubectl apply -f k8s/hpa.yaml

# Notes: Make sure the prometheus adapter is exporting metrics to the cluster
kubectl get --raw /apis/custom.metrics.k8s.io/v1beta1
kubectl get --raw "/apis/custom.metrics.k8s.io/v1beta1/namespaces/default/pods/*/http_requests"