Step 1: Create Namespace for Monitoring

kubectl create namespace monitoring

Step 2: Add kube-prometheus-stack Helm Chart Repository

helm repo add prometheus-community https://prometheus-community.github.io/helm-charts

Step 3: Install Prometheus using Helm

helm install prometheus prometheus-community/kube-prometheus-stack -n monitoring

Step 4: Update Helm Repositories

helm repo update

Step 5: Verify Prometheus Installation

kubectl get pods -n monitoring

Step 6: Create Nginx Deployment

kubectl create deployment nginx --image=nginx --port 80 -n web

Step 7: Expose Nginx Deployment as a Service

kubectl expose deployment nginx --port 80 -n web

Step 8: Verify Nginx Service Creation

kubectl get svc -n web

Create a Service Monitor YAML file. For example:nginx-service-monitor.yaml

apiVersion: monitoring.coreos.com/v1
kind: ServiceMonitor
metadata:
  name: nginx-monitor
  namespace: monitoring
spec:
  selector:
    matchLabels:
      app: nginx
  endpoints:
  - port: web

Apply the Service Monitor YAML file:

kubectl apply -f nginx-service-monitor.yaml

Step 9: Install KEDA with Helm:

Add the KEDA Helm repository:

helm repo add kedacore https://kedacore.github.io/charts
helm repo update

Install KEDA:

helm install keda kedacore/keda -n keda

Step 10: Create ScaledObject for Nginx Autoscaling:

Create a ScaledObject CRD file. For example:nginxScaledObject.yaml

apiVersion: keda.sh/v1alpha1
kind: ScaledObject
metadata:
  name: nginx-scaler
  namespace: web
spec:
  scaleTargetRef:
    name: nginx
  pollingInterval: 30
  cooldownPeriod: 60
  minReplicaCount: 1
  maxReplicaCount: 10
  triggers:
  - type: prometheus
    metadata:
      query: "sum(rate(http_requests_total{job='nginx'}[1m]))"
      threshold: "10"
      panicThreshold: "100"

Apply the ScaledObject YAML file:

kubectl apply -f nginxScaledObject.yaml

Get the ClusterIP and port of your Nginx service:

kubectl get svc -n web

Use curl to generate HTTP traffic to your Nginx service:

curl http://<nginx-service-ip>:<nginx-service-port>

curl http://10.102.253.44:80

Monitor the number of pods in the web namespace:

kubectl get pods -n web

Observe if the number of pods increases beyond the specified maximum replica count in your ScaledObject YAML file when there is more traffic.

Once traffic decreases, observe if the number of pods scales down to the specified minimum replica count.

Step 11: Add Karpenter Helm Repository

helm repo add karpenter https://awslabs.github.io/karpenter/charts
helm repo update

Step 12: Install Karpenter with Helm

helm install karpenter karpenter/karpenter \
  --namespace karpenter \
  --set clusterName=<your-cluster-name> \
  --set cloudProvider.name=<your-cloud-provider> \
  --set metricsProvider.prometheus.enabled=true \
  --set metricsProvider.prometheus.endpoint="http://prometheus-kube-prometheus-stack-prometheus.monitoring.svc:9090"

Replace with the name of your Kubernetes cluster and with your cloud provider's name.

Step 13: Create a Karpenter Provisioner YAML file

Create a YAML file (e.g., karpenter-provisioner.yaml) to define the Karpenter Provisioner configuration:

apiVersion: karpenter.sh/v1alpha5
kind: Provisioner
metadata:
  name: default
spec:
  requirements:
    - key: karpenter.sh/capacity-type
      operator: In
      values: ["on-demand"]
  limits:
    resources:
      cpu: 1000
      memory: 1000Gi
  provider:
    subnetSelector:
      kubernetes.io/cluster/<cluster-name>: '*'
    securityGroupSelector:
      kubernetes.io/cluster/<cluster-name>: '*'
    instanceProfile: <launch-profile-name>
  ttlSecondsAfterEmpty: 30
  ttlSecondsUntilExpired: 2592000

Replace with the name of your Kubernetes cluster and with the name of the launch profile to be used for new nodes.

Step 4: Apply the Karpenter Provisioner YAML file

Apply the Karpenter Provisioner configuration to your Kubernetes cluster:

kubectl apply -f karpenter-provisioner.yaml -n karpenter

Step 5: Monitor Karpenter

Monitor the Karpenter pods to ensure they are running properly:

kubectl get pods -n karpenter