Istio Demo

Simple demo App for Istio - leading service mesh for K8s, the demo consist of two nginx application (called as v1 and v2, to simulate different version of N application), use Istio features to control routing of external traffic to v1 or v2 application (load balancing, only to specific service, traffic shifting etc).

Prerequisite

In order to run the demo, user should have already:

1. Configured a working K8s cluster (cloud, barem-metal or VM)
2. Installed Istio (https://istio.io/latest/docs/setup/getting-started/)

Step 1: Deploy Sample Application

kubectl apply -f demo-deployment.yaml

Step 2: Deploy Istio Gateway and VirtualServices

kubectl apply -f demo-destination-rule.yaml
kubectl apply -f demo-gateway.yaml

Step 3: verifying Istio gateway is configured

istioctl analyze

Step 4: Validating

4.1 Access App v1 or v2 in round-robin manner within k8s cluster via Kubernetes service

• export SVC_CLUSTER_IP=$(kubectl get svc demo-nginx-svc -o jsonpath='{.spec.clusterIP}')
• export SVC_CLUSTER_PORT=$(kubectl get svc demo-nginx-svc -o jsonpath='{.spec.ports[?(@.name=="http")].port}')
• curl -s "http://$SVC_CLUSTER_IP:$SVC_CLUSTER_PORT"
• Calling the curl multiple times, user should noticed that the v1 and v2 application text shown randomly.

4.2 Access App v1 or v2 in round-robin manner outside k8s cluster via Istio Ingress Gateway

• export INGRESS_HOST=$(kubectl get po -l istio=ingressgateway -n istio-system -o jsonpath='{.items[0].status.hostIP}')
• export INGRESS_PORT=$(kubectl -n istio-system get service istio-ingressgateway -o jsonpath='{.spec.ports[?(@.name=="http2")].nodePort}')
• curl -s "http://$INGRESS_HOST:$INGRESS_PORT/"
• Calling the curl multiple times, user should noticed that the v1 and v2 application text shown randomly.
• Getting Ingress Host IP and Port is varies depend on cluster environment, more info https://istio.io/latest/docs/tasks/traffic-management/ingress/ingress-control/#determining-the-ingress-ip-and-ports

To play with Istio features

• Modifying VirtualService in demo-gateway.yaml
• kubectl apply -f demo-gateway.yaml
• curl -s "http://$INGRESS_HOST:$INGRESS_PORT/"
  • Through k8s clusterIP IP and port will not see the effects.

Route only to V2 app

apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: demo-nginx-vs
spec:
    .....   
    - destination:
        host: demo-nginx-svc
        port:
          number: 9080
        subset: v2
     ....

Route 90% of traffic to V2 app, and 10% to V1 app

apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: demo-nginx-vs
spec:
    .....   
     route:
    - destination:
        host: demo-nginx-svc
        port:
          number: 9080
        subset: v1
      weight: 10
    - destination:
        host: demo-nginx-svc
        port:
          number: 9080
        subset: v2
      weight: 90
     ....

Cleanup

kubectl delete -f demo-gateway.yaml
kubectl delete -f demo-deployment.yaml